How to easily fix your RV air conditioner.

This video describes how to replace the capicitors in an RV air conditioner.
CAUTION: Make sure to unplug your main power before working on the air conditioner.
Capacitors in alternating current (AC) circuits, like this air conditioner, don't store energy the way they do in DC circuits, but it doesn't hurt to be in the habit of discharging capacitors before working on them.
Capacitors in AC circuits are non polarized, meaning there are not positive or negative terminals, and the wires can be connected to either terminal.
My unit is a Coleman Mach, although other brands will be similar. When I turned on my air conditioner all it did was buzz so I took some steps to determine that the fan capacitor was not working. I identified the correct part, ordered a new one for $18.95 including shipping, and replaced it.
Here are the part numbers for the capacitors in my unit, although your unit might use different parts. Make sure that you order the same capacitors that came with your air conditioner.
Fan capacitor part # 1499-5461 7.5 MFD 370 volts
Run capacitor part # 1499-5721 40 MFD 370 volts
Start capacitor part # 1497-0871 88-108 MFD
I ordered my part through Amazon from:
RV Wholesale Direct
41 Triangle Court
Carrollton, GA. 30116
They shipped the correct part quickly and for free.

[@dmsteele92831]

Amazing!!!! Was just told today by an rv repair guy needed whole new unit and mine is doing same thing, if all goes well you will have saved me over a thousand bucks!!! Thanks so much!

[@TomandJulieMineExploring]

Obviously there are other things that can go bad on an air conditioning system besides the capacitors. If you can start yours by hand, and it works, the way I did in this video, it's the fan start capacitor. It's a very common part to fail especially when several years old.

[@taylors4243]

looks like the shaft needs to be oiled. when its stuck and wont come on without a little help, like you did with your hand, is because the shaft is rusted. keeping it nicely oiled will keep it running smoothly. there are rv techs that make a small tool to spin the shsft without even taking the shroud off by going through the slot, because it is the most common resolve for ac problems.

[@47AndyT]

There is a mentality today that you don't REPAIR you REPLACE parts insteaad! The military stated doing this years ago and it's a very expensive way of doing any maintenance!

[@stephenmillsmills3697]

Thanks for a great video. My Coleman ac was doing the same thing. Following your video I was able to fix the unit. I was sweating having to take to a shop to get repaired. But you saved the day. Many thanks.

[@TomandJulieMineExploring]

It's a pretty easy fix if it's just a capacitor. Glad you got the unit running and thanks for the nice comment, Stephen.

[@cathyhumphrey5615]

Thank you so much for the informative video on checking the ac capacitor and changing it out. What a relief to find out it is a quick fix and easy on the pocketbook.

[@TomandJulieMineExploring]

You're welcome, Cathy. Good luck with your repair.

[@patf.1961]

Thank you sooo much! You helped me confirm what I suspected...a bad Capacitor. And with your help, ID'd the Fan start Capacitor. You saved me so much time & money. Thanks again! ~ Pat

[@TomandJulieMineExploring]

You're welcome, Pat. Glad that you got it figured out.

[@definedecline]

i have the same unit on my rv, and it had the same problem. Opened it up and saw it has the optional start components and wiring, which had fallen apart. Gonna order them and put it all back together to be good as new! Thank you so much for this video, I was NOT looking forward to shelling out $$$ to be potentially ripped off! This is actually an easy fix!!

[@TomandJulieMineExploring]

Good luck on the fix. Thanks for the comment!

[@katbot2190]

So glad I found this. Thank you for sharing with all the rv owners out there.

[@TomandJulieMineExploring]

You're welcome, good luck with your AC.

[@timinole1]

Appreciate the video. The fan ended up turning on after replacing the capacitor but then after ten minutes it turned off again. On to the next video.

[@TomandJulieMineExploring]

Good luck, Timothy!

[@johnp5639]

Thanks so much for your time in making this detailed video.

[@TomandJulieMineExploring]

You're welcome. I hope it helps you, John!

[@danmclendon8561]

SUUUUUUPER HELPFUL!!!! I am really grateful for this video. My issue (I think) is the other capacitor- assuming the compressor isn't fried.

[@TomandJulieMineExploring]

Hope you get your AC fixed, Dan!

[@Kayden12gin]

We're hoping this is our problem. Going to check it out later! Thanks for the info

[@TomandJulieMineExploring]

It's the most common problem for the fan not starting. If all you hear is a hum or buzz when the AC tries to start there is a good chance this is the problem. Try starting the fan by hand as shown in the video to confirm.

[@joedirt8745]

Thank you so much for the time you take to help people its very much appreciated. I was successful after your help familiarizing me.

[@TomandJulieMineExploring]

Thanks, that's great.👍😁

[@RIPfifi]

Thank you so much for sharing! Saved us BIG time!

[@TomandJulieMineExploring]

You're welcome, David!🧊

[@josephcisneros9290]

This was exactly my problem. Changed my fan capacitor and it now works.

[@TomandJulieMineExploring]

That's great, Joseph. It's a common problem and an easy fix. Thanks for commenting!

[@garygale9875]

I have a 2000 fleetwood bounder. Gonna check in the morning to see if this is my problem👍 ty for the heads up

[@TomandJulieMineExploring]

If you can start it by hand a bad capacitor is most likely the problem.

[@pontevedra9639]

You da man!!! I had exact symptoms, I watched your video, ordered the part and replaced it and it works!! Thanks!!

[@TomandJulieMineExploring]

Pretty easy fix once you know what the problem is. Thanks for the comment!

[@pontevedra9639]

I added the fan capacitor and it worked for a day and then went back to same problem, I then replaced the start and run capacitors!! That seemed to solve the problem!!

[@TomandJulieMineExploring]

@@pontevedra9639 Thanks for adding that information.

[@alvaroaguirre252]

Great video. I have the same AC problem, the fan runs only when I give it a push. Will try to replace the capacitor.

[@TomandJulieMineExploring]

Thanks and good luck with your fix.

[@NorthwestCatch]

Thanks so much. Great video and super helpful.

[@TomandJulieMineExploring]

You're welcome, hope you get things running.

[@davedeatherage4902]

Thanks Tom I just learned something from this video. 👍🏻🇺🇲

[@TomandJulieMineExploring]

You're welcome, Dave!🙂

[@EverydayProjects]

Thanks. Well done. I have the same unit and I've just posted a video of me testing the unit on the bench.

[@TomandJulieMineExploring]

Thanks, I'll check it out.

[@greggaxiola]

Really well done, Thank You Sir.

[@TomandJulieMineExploring]

You're welcome. Thanks for watching and for the nice comment, Greg.

[@tinger99]

Saved me a bunch of money, thanks!!!

[@TomandJulieMineExploring]

You're welcome, sir. Thanks for the comment!

[@YankeesOutdoorAdventures]

Great information brother keep up the good work👍

[@TomandJulieMineExploring]

Thanks, Yankee!

[@pmae9010]

Nice job guys, I am a 'fixer' too, it's fun and saves a bunch.

[@TomandJulieMineExploring]

This is a very common problem and super easy and inexpensive fix. I've had many comments of people saving $$.

[@georgejungle2255]

Thanks man! Will check this tomorrow.

[@TomandJulieMineExploring]

Yeah, if you can start it by hand like I did in the video it's usually a capacitor.

[@cylekeltner1261]

Dude...boom you saved me such a headache! Thank you

[@TomandJulieMineExploring]

You're welcome, Cyle. Happy to help a fellow guitar player.

[@randyhughes801]

Great video...good camera and no talking about irrelevant stuff!

[@TomandJulieMineExploring]

Thanks for the comment, Randy!

[@randyhughes801]

@@TomandJulieMineExploring You bet. And thank you! Got the my AC working again this weekend with the new Capacitor and your video!

[@TomandJulieMineExploring]

@@randyhughes801 That's great!

[@mrtosh]

Excellent video! Save alot of people time and money.

[@TomandJulieMineExploring]

Thank you. It's a very common ptoblem.

[@Carlbakerlandscaper]

Fantastic video and tutorial to help change capacitors! changed them both myself, was so proud of myself! Now i have to have someone change the fan motor because it wasn't the capacitors, The good thing is, they say you should change the capacitors wen you change the fan motor, so somethings done

[@TomandJulieMineExploring]

I'm happy that you found the video helpful and thanks for the nice comment, Carl. If your motor wouldn't start by manually helping it, usually it is not the capacitors that are bad. Are you sure it's getting power? Hope you get it fixed soon!

[@Carlbakerlandscaper]

I actually changed the motor myself after watching some youtube videos,. I ordered it on Amazon, was not difficult to install and AC works! very quiet now, I like that the capacitors are changed also before going into Florida summer! they were very rusty and looked original

[@TomandJulieMineExploring]

Carl B That's great. KZbin can be an awesome resource most of the time. Glad you're all fixed up and ready to go.

[@adobemastr]

Carl, I'm having the same problem: my fan motor is seizing up; I'm assuming I have to replace it. What videos did you watch to figure it out?

[@Carlbakerlandscaper]

Coleman motor replacement-Donald Mcadams was best, and a couple others, the I just did it. and Im no mechanic, working great still!

[@maybe-probably]

Thanks the the instructional video!

[@TomandJulieMineExploring]

You're welcome and thanks for the comment.

[@sougougyoutoku]

Recently Polar cub of my campig car running　for about 11 years broke down. In Japan very few people know the trouble-shooting of American air-condithoner. Once I dicided to buy a new Mach8. But accidently I came across your video. So I exchanged the start capaciter and 　then　the air-conditioner restored immediately. I appreciate this video and you. Thank you very much. d(^o^).

[@TomandJulieMineExploring]

You're welcome. Glad you got it running again!

[@ColinMacKinnon]

Thanks for the tips. Fingers crossed.

[@TomandJulieMineExploring]

It's a very common problem. If you can start it by hand it's usually a capacitor.

[@raymondgross6419]

Thank you. My problem is not in the fan,but appreciate the part numbers.

[@TomandJulieMineExploring]

If you are changing out the caps match them to what you have in there now.

[@johnford8411]

Thank you! My capacitor was 28 dollars but it was only one for the entire RTU. #ZeroDollarsOnLabor

[@TomandJulieMineExploring]

I like the $0 on labor.

[@billykidd6971]

Nice video, You were concerned about the capacitor being bigger than the other one and you needed to expand your band. I had the same problem and just used zip ties. been holding for 5 years now.

[@TomandJulieMineExploring]

That sounds like it's working for you. Thanks for your input!

[@SixStringSteveDelivers]

Excellent info and video sir! Ours started making the same buzzing noise this evening after my wife turned it off, then back on several minutes later. It had been running fine all afternoon. I'll check it out tomorrow and now know what to do.

[@TomandJulieMineExploring]

Good luck with your fix. If you can jump start it by hand the starting capacitor is bad.

[@SixStringSteveDelivers]

Tom Wigren, OK. I'll get back to you and let you know what happens. Thanks

[@SixStringSteveDelivers]

Tom Wigren, Yep, this is exactly what is wrong with mine. I have a Coleman Mach AC unit. I'll get the capacitor ordered. If I have other issues can I ask you for assistance?

[@TomandJulieMineExploring]

I'm happy to try and help you if I can.

[@SixStringSteveDelivers]

Tom Wigren, I need the fan capacitor, correct?

[@timshaw6653]

Thank you for the video

[@TomandJulieMineExploring]

You're welcome, Tim. Thanks for the comment!

[@joemorrow8411]

Nice job👍👍

[@TomandJulieMineExploring]

Thanks, Joe!

[@joannebourg828]

New to camping. Have an old dometic duo therm RV ac. It cooled on Friday night and part of Saturday then it seemed to cycle frequently then it tripped the breaker a few times then it no longer tripped the breaker but no longer cooled and was making a noise that got a bit louder, turn all off the next morning Praying I don’t need a new system. This women needs some AC tech help, thank you

[@TomandJulieMineExploring]

If you are tripping a circuit breaker on your RV's electric panel something is drawing more current than it normally should. Your fan (blower)motor or compressor motor could cause the circuit breaker to trip. Does the fan work without turning on the actual air conditioner? Many thermostats have a fan only mode. This would tell you if your blower motor is working properly. Your compressor motor is the other thing that could trip the breaker if it's going bad. Your compressor can also cycle on and off if it's overheating as there is a thermal shutoff on it. It will try to start again after it cools for a few minutes. You should be able to hear your compressor if it is running or not. I've tried to explain how to simply diagnose if both the electric motors in your system are working. Refrigerated air conditioning is a somewhat complicated process with several things that can go wrong. If either of your motors aren't working properly you will probably need a professional service person to fix the unit.

[@raulperez1123]

Thanks you soo much!! You done save me a few hundreds dollars!!!

[@TomandJulieMineExploring]

You're welcome, Raul. I hope you got it working.

[@raulperez1123]

I sure did thanks to you!! 👌🏽👍🏽

[@taewilson9273]

Thank you ! now my A C is fixed

[@TomandJulieMineExploring]

Glad that you got it fixed. Thanks for the comment, Tae!

[@walterhandley4959]

Thank you! I thought it was my start capacitor. My unit was acting the same way even after replacing it. Im going to replace the fan capacitor and see if it works.

[@TomandJulieMineExploring]

I hope you get it running correctly.

[@walterhandley4959]

So I replaced the fan capacitor and it started functioning better. Started on it's own and ran for about 30 mins before it starts to die down and stop spinning. Do you know what that could be?

[@TomandJulieMineExploring]

Make sure you have good power to the unit and sufficient amperage for what it requires, especially if you are running more than one AC unit. If the fan motor is spinning freely when you spin it by hand when cold then something (bearings?)might be over heating after running for a period of time. Blower motors don't last forever and you have already fixed the easy things.

[@katalackatt76]

Thank you so much for this great video, you made it very easy to understand. I was also wondering if you know anything about RV converters?

[@TomandJulieMineExploring]

I know that the converter/transfer switch can be a fairly complicated system with many different setups. So, no I don't really know about them. I'm having trouble with mine as we speak. Thanks for the comment!

[@paulb4400]

Paul and Julie thank you!

[@TomandJulieMineExploring]

You're welcome, Paul!👍😁

[@DanPressler]

Hey Tom! I just replaced the same capacitor in my roof mounted AC unit which was very similar to yours (mine is a Coleman Mach series in a '94 Jayco popup). I used your video to determine the cause of my AC fan not working (compressor would come on but no fan) and also exactly how to replace the fan capacitor. When I took all the covers off the unit that needed to come off, everything looked almost identical to yours, even the plumbers strap :). So thank you for doing your video, my fan and AC work perfectly now. Just FYI...prior to replacing the fan capacitor, I had replaced my converter from the original Carson which was making a loud humming noise and some DC systems were not working properly and I think may have been responsible for the AC fan capacitor to go out, maybe? Anyhow, I put in a Progressive Dynamics PD4135KV Inteli-Power Converter with Built-in Charge Wizard and everything now works as it should...Again, thanks for the video, Tom!

[@TomandJulieMineExploring]

Thanks for taking the time to add a nice comment, Dan. I appreciate it and I'm happy that you have everything up and running properly. You probably even saved yourself a few bucks.

[@DanPressler]

@@TomandJulieMineExploring ...Oh, for sure...paying someone to install either the converter or the capacitor was not in the budget...not to mention the hassle of having to take it somewhere, probably leave it and then having to go back and pick it up....definitely DIY saved me big $$$'s ;)

[@MrTatts64]

Nice work Tom. Electrics and I really don't mix. I cant understand the stuff and it always seems to be trying to turn my hair Afro!

[@TomandJulieMineExploring]

Thanks and it's safer if you can unplug the thing you're working on. Your hair will thank you.

[@Wayman_Simmang]

thanks for the video!

[@TomandJulieMineExploring]

You are welcome, sir.

[@jimmiller9178]

Thank you! I'm pretty sure that is my problem. Fan will only run on low I get a buzzing on high. My only concern is in not sure I can walk in my travel trailer roof...

[@TomandJulieMineExploring]

You're welcome, Jim. Good luck with your fix.

[@IsaacCarmichael]

You are a life saver

[@TomandJulieMineExploring]

Hope you get your machine running, Isaac.

[@firemanrh]

Great video!!!!! you talk about shorting out the capacitors. when doing so, do you turn off the main power switch inside the RV and then lay the screwdriver across both terminals? Thank you in advance.

[@TomandJulieMineExploring]

Unplug the main power cord for the RV when working on the capacitors. Capacitors in an alternating current circuit normally won't be storing any energy.Thanks, Richard.

[@jonnyf3452]

Great video not sure if this is my problem but still a good tutorial

[@TomandJulieMineExploring]

If you can start your fan by hand and the system runs then a capacitor is bad.

[@jonnyf3452]

@@TomandJulieMineExploring my AC is currently working however it makes a loud humming/vibration intermittently and then goes away. I'm going to check it out up top soon but it's literally 40°C out right now 🙄

[@TomandJulieMineExploring]

Could be a fan motor or compressor problem. Maybe you'll be able to tell where the vibration is coming from when you go up top.

[@jonnyf3452]

@@TomandJulieMineExploring I'll check it out thanks for the advice!

[@richardwarnock2789]

Its always great to have spares and that bimetal plates for the condensor cause they rust that unit looked great than!!!; )

[@TomandJulieMineExploring]

Thanks, Richard. 👍

[@MyGoatShedLife]

Thank you so much. This was greatly helpful!!!!

[@TomandJulieMineExploring]

You're welcome. I'm glad it helped and thanks for subbing.

[@judysaeler4264]

My air conditioner is making loud noise why

[@justinprince9507]

I have a 13,5kbtu Coleman Mach and I lost low fan but high fan works. Was wondering if it’s a capacitor issue?

[@TomandJulieMineExploring]

Hi Justin. First off, I am not a certified AC tech. The three caps are to start the fan, run the fan, and run the compressor. I suppose it could be a capacitor problem, but it seems more likely a thermostat, switch, or wiring issue. I would look for ways to troubleshoot the thermostat first. Good luck with the fix.

[@promisestarxd9487]

thank you!

[@TomandJulieMineExploring]

You're welcome. I hope you get your machine working.👌

[@froglobster]

My Coleman Mach motor was running then stopped to humming. Spun by hand only got running on fan, - but some reason I don’t know would not work on cool unless I waited 30 seconds on fan before switching.after 30 seconds I could flick to cool but only lasted 10-15 minutes working proper-then started squeaking then humming. Pulled the motor off despite 50 unhappy wasps with several nests in the shell. Anyways a little motion back-and-forth pulling tugging on the shaft is OK and it’s the bearings but up and down action is the bushings and I had up-and-down action on the shaft so my bushings on the motor is shot. In that case replace the motor or find a shop that can get a bushing for it and I couldn’t find a shop that would do bushings-are hard to come by and the unit 20 years old so I bought a new Motor. I just got the motor and fan cap yesterday near the end of July but I’m not sure about the other capacitors you are talking about.

[@TomandJulieMineExploring]

There are three capacitors in this circuit. One for the AC compressor, one to start the fan motor and one to run the fan motor. I would replace all three.

[@froglobster]

@@TomandJulieMineExploring Thanks

[@shannondoyle7437]

Thank You !!

[@TomandJulieMineExploring]

You're welcome, Shannon.

[@LSwaggy]

Are RV A/C and Heat units interconnected to a car's radiator, or are they their own separate unit?

[@TomandJulieMineExploring]

AC is a separate unit mounted on top of the RV.

[@charlykeyser1350]

On the very top of your open compartment it looks as if there is a black relay? What color wires go to that? My unit is missing parts and I'm trying to figure it out

[@TomandJulieMineExploring]

Honestly I can't recall what's there. You might see something listed on you schematic that could help.

[@amydiane21]

After hours of searching, I finally found your video that is the same as mine. My fan is running fine, but my compressor won't kick on. Would one of the other capacitors be responsible for that?

[@TomandJulieMineExploring]

That's a definite possibility. There could be other causes as well, but the capacitor that runs the compressor is a good place to start. There are two capacitors that start and run the blower fan, and the other runs the compressor. The thermostat, wiring, insufficient power supply, bad thermal cutoff, or bad compressor are also possibilities for your AC problems. If you look at your wiring diagram, you will be able to figure out which capacitor is for the compressor.

[@blacksunapocalypse]

Any idea what might be the problem when there is no response at all from the AC unit? Replaced thermostat to no avail. Power IS getting to the control box and to the capacitors.. I tested the capacitors themselves and they SEEM fine, but I was told by others that they may still be faulty? Two of them are pretty rusty, if that means anything.

[@TomandJulieMineExploring]

I'm assuming that the compressor is not running as well as the blower fan. There is sometimes a thermal overload cutoff on the compressor, but they reset after cooling down. Maybe a power surge took out all the capacitors at once? That's odd to have power up to the caps but not to the fan motor or compressor. I guess you could replace the caps, especially if you are planning on getting he unit repaired if it's something major as that is something that would be done anyway. Wish I could be more help.

[@TheDoogman]

my fan and compressor come on but not cooling much can a capacitor make it run slower causing issues too?

[@TomandJulieMineExploring]

The three capacitors help start and run your blower motor and compressor. If both are running I don't think a capacitor is the problem. A dirty condenser, low refrigerant condition(which means a leak somewhere) plugged drier/filter, or a compressor malfunction could be the problem. It won't hurt to replace the capacitors if you are planning on getting the unit fixed as you would want to replace them anyway if you are going to replace the compressor, for example.

[@texaswalkerwoman9875]

thank you

[@TomandJulieMineExploring]

You're welcome!

[@CHINOTADEO]

Hi Jim I haveaproblem can you help me ? When I turn on m ac (4 wind 1994) I heard a click but nothing happens do I should switch the capacitors?

[@TomandJulieMineExploring]

They are complicated units where a number of things could be wrong. Anything from a thermostat, power supply, loose wire etc. one if the capacitors could also be the problem and is fairly easy and inexpensive to fix. Sorry that I can't give you a definite answer over the internet.

[@avalon1rae]

Thank you

[@TomandJulieMineExploring]

You're welcome!

[@Its-Mrs-Ladd]

Mine hums and the fan is trying to turn very very slowly but can barely turn. I checked the fan for debris and obstructions and it's clean. When I try to give the fan a push start with my fingers it still won't freely spin....just very slight jumpy movements. Any ideas on what might be causing this?

[@TomandJulieMineExploring]

Make sure you have a good power supply. Check that the fan spins freely with no power to it. If it does spin freely but won't start, I'd try new capacitors. If the compressor is running, I would replace both start and run fan capacitors. Good luck!

[@Mar--]

Hey so my ac has started doing the same thing. Most of the time it works as it should, but sometimes I have to spin the fan by hand to get it going (3 times so far in the last week). The other day however it wouldn't start all day even by hand spinning it then it decided to work out of nowhere. Do you think the capacitor or fan motor might be going bad?

[@TomandJulieMineExploring]

If it were me I would replace all of the capacitors. If the motor is going bad and needs to be replaced you would normally replace the caps at the same time as the motor anyway.

[@brianmoore3949]

Does anyone know what the three parts are called it looks like one is a fan capacitor and one is motor capacitor and not sure what the other one is called but I have to replace all 3 of those capacitors and some of the wires need to have new ends put on do to some of the wires were melted and looks like this was going on for a while but it does hum like it wants to start but obviously it’s not until I do some repair work and if anyone can tell me where to get these and what exactly they are would be great do to I’m disabled and can’t afford a new unit.. Thank you

[@TomandJulieMineExploring]

Hi again, Brian. Make sure you have a good power supply as the melted wires don't sound good. The three capacitors are as follows. One to start the fan motor, one to run the fan motor, and one for the AC compressor. When the fan won't start, it's usually the start cap that's bad. I believe I put the place that I ordered them from in the video description. If you can't find it there, please let me know. Good luck getting your machine running.

[@volt8399]

I am currently going through a journey with my RV AC it looks like a very similar model as yours. It randomly turns off in a very inconsistent manner. I think its outdoor temperature sensitive to both above 90 and below 60. When it randomly turns off it also temporarily disables the thermometer inside the RV. Turns back on/becomes responsive after maybe 3 minutes? It usually runs for about 15 mins before turning off. I was taking a look around and found that the controller was sensitive to being moved around, it as if it experiences a momentary short but not enough to shut down the unit. I dont know if this is the same reason that I experience of it completely shutting off, however its ofcourse still a problem. Ordered a replacement controller, and just as I was switching the controllers found that the black power cable had a cut on it and could potentially be touching the exposed grounding wire as I was moving the controller. I electrical taped it, reconnected the old controller and tested it again, and the problem still exists. I will now attempt to change the controller one more time to the new one and see if this fixes the problem. Since the system starts just fine I think I can safely assume that the capacitors are fine? The only other potential issues I can think to check is make sure that the gas pressures are what they need to be, which I need to figure out how to do on these units. We shall see how it goes!

[@TomandJulieMineExploring]

Many of these have a thermal overload cutoff that will shut down the motor if anything gets too hot. Often, this is caused by an insufficient power supply, like using an extension cord etc. It sounds like your starting circuit is working but one of the caps is for the 'run' circuit. I suppose that could be causing a problem. Electricity can do some strange things. Good luck with it.

[@volt8399]

@@TomandJulieMineExploring thank you for your response! I will keep that in mind

[@TomandJulieMineExploring]

@volt8399 also know that if it is a thermal cutoff that's being tripped, it will reset itself after things cool down. Usually 15 minutes or so.

[@volt8399]

@@TomandJulieMineExploring Ok Im pretty sure my reset time is less than 5 minutes, so it might be safe to rule ot a thermal cutoff, but I do need to test it again and time it.

[@pellonda1]

Hi thank you for your video my ac unit I have to also give it a hand spin to start the fan then the fan works fine but when I turn on the cool sistem in less than a minute it cuts of the main relay you think I should also replay all my capasitors?

[@TomandJulieMineExploring]

Hi Pedro, It sounds like you at least need the fan capacitor and it wouldn't hurt to replace the others at the same time. That’s the easiest place to start and not too expensive. It's possible your fan motor or compressor is drawing excessive current causing the circuit breaker to trip. Good luck with your repair.

[@pellonda1]

@@TomandJulieMineExploring thank you so much I had a tech that came look at it today and didnt eaven look at it and told me I need a new unit bc he says the only thing that causes the ac to trip the breaker was a bad compressor and he says I need a new unit hes quote was 1700 for a new one installed I will be taking out the capasitors and start from there it dosnt hurt and thank you for letting me knw

[@TomandJulieMineExploring]

Oh that sounds expensive. I hope you get it fixed, Pedro.

[@korissamoya5537]

How old was your unit? My fifth wheel ac made a loud popping noise then buzzed. I figured it’s just dead since I’m guessing it’s as old as the trailer (18 years) curious if this may just be the issue!

[@TomandJulieMineExploring]

It was about 14 years old when we did this fix. It's fairly easy to diagnose this problem. If you can safely get on top of your rig and take the shroud off, you can try to hand start it like you see me do in the video. If it starts up and everything works you need a new fan capacitor. If the compressor is not running it could be the other capacitors. Obviously it could be something worse, but, you always want to start with the easy and inexpensive fixes first. Good luck!

[@Marmar34082]

I have the exact same issue but I changed the capacitor and it’s still doing the same thing. It buzzes and when I try to spin the fan to start it, it will only spin for a second and stop and just hum again. Do you think it would be the start capacitor?

[@TomandJulieMineExploring]

The fan uses two capacitors, a start and a run. In my video I showed the fan not running until being started by hand and then running fine. That was a bad start capacitor. If you can't start it by hand then it could be a bad run cap. If that is what you already replaced then you might have some other issue. Make sure your compressor is running, too. Some poeople prefer to replace all the caps to eliminate them as a problem. Hope this helps.

[@barker31155]

Personally from my experience given that all the capacitors operate in the same environment I would replace all 3 and not have to go after it again in the nearer future. Save the pain now. They won't be any cheaper in the future.

[@TomandJulieMineExploring]

That is sound advice. I've not had any problems with the other rwo caps in my system, yet. Replacing them all is definitely a good option. Thanks for your input.

[@carolyncunningham3847]

Can you tell me why my AC unit runs great unless the outside temperature gets to 100F or more?? Thanks

[@TomandJulieMineExploring]

It's possible your AC just isn't capable of keeping up with that high of an outside temperature. Keeping filters and coils clean will help. I doubt that there is anything wrong with it if it works fine at lower temps.

[@litmystic5390]

very nice video, thank you. my ac works, but the air is pretty warm right now comming out of it. can i fix this at home?

[@TomandJulieMineExploring]

If your fan and compressor are both running it won't help to change capacitors. If you have to hand start it like I did in the video then new capicitors could be the fix. Depending on how hot it is outside where you are right now it's possible your air conditioner just can't keep up.

[@litmystic5390]

@@TomandJulieMineExploring thank you! yes it seems to work when its not Quite so hot (???) (it was 100 today)

[@TomandJulieMineExploring]

It's possible that it just can't keep up when it's that hot. RV's aren't insulated as well as a house.

[@elcocoreyes]

i had a question i had an rv with an AC and thermostat. i got a newer RV and this one doesnt have a thermostat. it has a dial to control the temp. when the AC is on, compressor kicks in and the fan kicks in. lets say i have the thermostat set to half way. the compressor kicks out when the desired temp is reached but the fan keeps blowing. what happens is that immediately the humidity starts climbing for example from 50% to 90% and makes it very uncomfortable in the RV. ive tested some different scenarios. when i hear the comp kick off, i walk up and turn the fan off too and the humidity stays at around the same like 50% stays at about 50-55% my question is....is there a way that i can rewire the FAN to turn off with the compressor? i thought of rewiring it at the capacitor. is that ok or does anyone have any other ideas? i want the compressor and fan to work together. comp off, fan off. comp on, fan on.

[@TomandJulieMineExploring]

Diagnosing AC problems over the Internet is never going to be ideal. I would not attempt to rewire the system. The fan switch...on/auto/off could be set incorrectly. The thermostat could be defective and needs to be replaced. The fan wiring could be wrong, damaged or loose. On some units the blower fan will run on if the condenser is icing up in an attempt to thaw it. Air flow could be restricted by a dirty filter or dirty condenser. The refrigerant level could be low causing the condenser to ice up. This is all I can think of off hand and I hope you get to the bottom of it.

[@lauriezacco4324]

Had something really bizarre happen today. We came home to our 1996 34j Fleetwood Bounder and was putting groceries away and about 45 minutes later the front ac came on all by itself. It was flickering on and off. When it was off i could hear the ac unit itself clicking. I wiggled the on off switch on the thermostat and it didn’t make any difference. The light on the thermostat wasn’t ever on. It stopped coming on and the ac unit itself was just clicking. I unplugged from the 30 amp pedestal and it was still clicking! So I went on the roof and took off the shroud and took off the metal shroud to get to the wires. I unplugged the main pigtail but it kept clicking. I saw the 4 clips with wires on them and unplugged the fat white wire and it quit clicking. It was getting dark so I put it back together pretty confident that I had disconnected it. Any ideas what could cause this and what should be replaced? Could it be the start or run capacitor??

[@TomandJulieMineExploring]

It's obviously not ideal to diagnose electrical problems over the Internet, but, many times a clicking noise coming from the refrigeration unit is a start relay gone bad.

[@andrewzinthefer9385]

I have a wilderness gl 27h and the ac turns on but doesnt cool,and the high and low automatic does not work.What would be wrong with it?

[@TomandJulieMineExploring]

The first things I always check for is to see if the circulating fan is running and if the compressor is running. The circulating fan is what blows the air around and is what I started by hand in this video. You will have to listen for the compressor to tell if it is running usually easiest when you have the AC shroud off.

[@michaelmoreno2072]

What mfd should the fan capacitor read when you test it? I got 008. But the the capacitor reads 7.5 to 10 I think. Is my capacitor still good, or do you think my fan is bad? Thanks in advance.

[@TomandJulieMineExploring]

Michael Moreno There is a run and a start capacitor for the fan. If you can start the motor by hand it's the start capacitor. If it doesn't run at all it could be the run capacitor, the motor or some other issue. The capacitors wear out after a while and are fairly inexpensive so it is usually a good place to start. I hope that helps answer your question.

[@michaelmoreno2072]

Tom Wigren ok thank you, I'll give it a try.

[@PAULMOB1]

That capacitor is 7.5. Plus or minus 10% You need a meter that reads mfd to check them

[@Infidel1967]

Do you know what the little black box is right above the capacitors? I believe it is a switch that is causing my ac to run about half an hour then turn off for ten minutes or up to half an hour.

[@TomandJulieMineExploring]

Compressors have a thermal protection cutoff that prevents damage to them from overheating. That sounds like what is happening to you. There are different reasons for overheating and sometimes just a high ambient temperature can do it. A little research on that topic might get you some answers.

[@Infidel1967]

@@TomandJulieMineExploring Thanks - That's been my latest thoughts too. I traced out the wiring on paper and there is no way it could be a switch. Has something to do with the capacitors. Other than the main switch and the thermostat it's a direct connection to the compressor and the fan motor.

[@rodrigocastillo9593]

On my ac the fan turns on but it just won’t cool what capacitor would that be?

[@TomandJulieMineExploring]

You can usually hear if your compressor is running or not. If it is not running, you could try replacing the run capacitor. The start and fan caps sound like they are working. There could be other issues if your compressor is running and not cooling. Low on refrigerant would be a common issue.

[@waynestriano7272]

The AC unit does not power on from the switch, I checked the breaker it's fine, can it be one of the capacitors?

[@TomandJulieMineExploring]

You should be able to hear the compressor running, or the fan buzzing trying to start if a capacitor is bad, if you have power to the unit. I would double check for good power and make sure the thermostat is good. I suppose it's possible that all your caps are bad. Not likely though, imo.

[@allenramsey1825]

How did you determine that it was the fan capacitor and not the hard start capacitor ?

[@TomandJulieMineExploring]

Because the fan motor wasn't starting until I spun it by hand. Plus, I don't have a hard start capacitor.

[@brianmoore3949]

Hi my name is Brian and I have a 2004 Winnebago sightseer and ac doesn’t work but it looks just like yours and I was took panel off and some wires were melted but I need to replace all 3 of those capacitors and was wondering if you could tell me what each one was and where I can order them or a diagram or whatever you can help me with

[@TomandJulieMineExploring]

Hi Brian. There are many different AC units, so I can't tell you exactly what capacitors you need. They should each be marked so you can replace them with the same ones. If not, there should be a schematic sticker near the area where the caps are like you see in my video that might have the information on it.

[@brianmoore3949]

Ya it doesn’t tell me the part numbers or where you got them so that will be helpful and thanks again

[@TomandJulieMineExploring]

I put the part numbers for my unit and the ordering information in the video description.

[@ragnarlothbrok1147]

MY AC DOES NOT TURN ON OR BLOWS AIR, ALL I HEAR WHEN I TURNED ON IS A IS A CLICK AND THATS IT AND I DONT KNOW WHAT COULD BE, ANY SUGGESTIONS? Thank you.

[@pilotnelson4507]

SOCIALISM SOCIALIST capacitor. That's vwhat this post is all about. If you are not comfortable with 110v service, DO NOT DO IT YOURSELF. Find someone with the experience and basic electrical safety tools.

[@randygarza3001]

Hello, I have a 5th wheel RV. My AC stopped working. I replaced the whole A/C unit on top of the RV. Connected everything and its not working. What do you think?

[@TomandJulieMineExploring]

I can only guess at the common things. Thermostat or thermostat wiring, power supply problem. I'm not sure if your setup has any other switches involved. Things like that.

[@enochjames5452]

Most common thing is circuit breaker switch for ac get the switch with one that has gfci built in

[@wm5297]

I get the buzzing sound and the fan rotates very very slowly then stops. If it doesnt start by hand, do you think it still might be the capicitor?

[@TomandJulieMineExploring]

If it won't start by hand it could still be a capacitor. I would replace them all. If you are going to fix the unit then you will be replacing the capacitors anyway, so it's a good, and reasonably priced, place to start. If you end up having to replace the motor you will be starting with good caps.

[@wm5297]

@@TomandJulieMineExploring well, I replaced the fan capacitor to no avail. I cranked it and it worked, but then stopped on its own. After letting it sit a while, I tried again and it turned on fine - but once I switched to low fan speed it puttered out on me, and it wont turn back on to high. Perhaps its the motor or some kind of electrical issue?

[@TomandJulieMineExploring]

I would replace all the caps. If the motor needs replacing you will want new caps anyway.

[@dwightwalker2009]

I have a white wire and red wire behind the refrigerator in my camper not hooked up do it goes to air-conditioner?

[@TomandJulieMineExploring]

Sorry, I really wouldn't know about those wires.

[@dwightwalker2009]

My air would come on but its blowing hot air

[@TomandJulieMineExploring]

@dwightwalker2009 You can check to see if the compressor is running.

[@jenniferslywczak8911]

Question, you mention the three capacitors, and our unit has three capacitors as well. How do you know which capacitor is the problem, which one to change?

[@TomandJulieMineExploring]

Are you able to start the unit by hand like I did in the video? If so, that's a bad fan capacitor. If the compressor is not running that could be a problem with the other two capicitors. Some people think it's a good idea to replace all three capacitors while you're doing this job, which does make some sense. I hope this helps and good luck with your repair.

[@TomandJulieMineExploring]

If you are having trouble figuring out which capacitor is which you can go by the color of the wires in the schematic that lead to it.

[@maddisondewitt1297]

Hello, I was trying to figure out why my refrigerator in my rv wouldn’t run on electricity. After inspecting it I found that the 12v wire wasn’t snug around it’s terminal so I adjusted it so it would fit. And while doing that I accidentally touched it to the ground wire. It was unplugged so there was no power but it blew a fuse witch I replaced and it still won’t run on electricity. Did I cause some kind of damage somewhere else in the system? Please help.

[@TomandJulieMineExploring]

If you blew a fuse chances are you didn't ruin anything. That's what fuses are for to protect the components in a circuit. It's possible your 110 volt heating element has stopped working. That's what the refrigerator runs on when using electricity. It's a ling thin rod with a standard electric cord and plug attached to it and plugged into the control board. They are not too difficult or expensive to replace. Of course it could be another problem, too.

[@raymondlanier1112]

I’m glad you got it fixed but guessing is not a good rule

[@TomandJulieMineExploring]

Not sure what the rule is that you mention, Raymond. It's an easy fix to a very common problem. Thanks for commenting.

[@pilotnelson4507]

Try not to oil "oiless" bearings. It may seem to help at first, but the oil used may not "agree" with the sealed bearing... And could cause a grease fire from friction and a bad bearing. Instead of just seizure, it may ignite the grease.

[@TomandJulieMineExploring]

pilot nelson Thanks for your input.

[@matpn2359]

thanks

[@TomandJulieMineExploring]

You're welcome.

[@bball111454]

Did this make the breaker kick out ? My friends A/C breaker kicks out sounds like the compressor is running.

[@TomandJulieMineExploring]

It did not trip the breaker. Sounds like something is drawing too much power, or the breaker has gotten weak, which they can do after tripping several times.

[@bball111454]

Thank You for the speedy reply, I am going over to check it out. May be the compressor start capacitor ,

[@TomandJulieMineExploring]

@@bball111454 You're welcome.

[@KARTo0oS]

it looks to me its Coolman Mach3 AC. Could you let us know the part number for the compressor?.

[@TomandJulieMineExploring]

I'm sorry I don't have that part number.

[@marcrobson1517]

I am unclear on which capacitor to replace. Your comments suggest the STARTING capacitor, but your video showed the FAN capacitor on the diagram and then the repair seemed to continue that thought. In my case there is a loud buzz/hum and if i start by hand it turns/blows great for 1 to 6 minutes and then stops on it own and resume buzzing. i can spin by hand again and get same results. So I THINK I need to replace a capacitor but not sure which one :)

[@TomandJulieMineExploring]

Not sure what exact unit you have, but, it sounds like you might need to replace more than one capacitor if it won't start by itself, and, once started, it won't keep running. Replacing the capacitors is relatively inexpensive and easy to do. It's always the easiest place to start on the AC repair. I would replace them both if it were me.

[@marcrobson1517]

thanks - I have identified my 3 capacitors and am ready to order replacements but one last question. The start capacitor has a little box on top of one of the terminals. It looks sort of like an add-on. When I search amazon I see similar pictures of capacitors that describe it as a hard start kit. No idea what that is but those cost about four times the plain capacitor. Any thoughts?

[@TomandJulieMineExploring]

The hard start kit is an add on that is supposed to be more efficient in helping start your AC compressor. Is your compressor working currently even when your fan is not? You might not even need a new capacitor for the compressor if it's running fine. It won't stay on long without the fan running, but you can tell if it starts correctly. You should be able to hear and feel it running, and rumbling, even if your fan is not working. That is how mine was. If you watch in the video my compressor starts up before I hand start the fan. I think the compressor is usually set up to not need a hard start kit, but, you may choose to get one. A little research should help you figure it out.

[@brandonstanford5039]

What if when you turn the a/c off you hear the humming noise?

[@TomandJulieMineExploring]

You would have to go up top and listen for where the noise is coming from. If the blower motor is working properly it shouldn't be humming when it's off. Sorry I'm not much help on that one.

[@stuhayes2010]

Can I use a multi-meter to check a capacitor? If so, how?

[@TomandJulieMineExploring]

No, I don't think so, you need a different type meter.

[@edmalts]

Hi Tom. I have same unit but my a/c turns on and shuts down after 2 seconds. ------ fan works on fun position.

[@TomandJulieMineExploring]

There is a thermal shutoff that will cut power quickly to the compressor if it's drawing more current than it should be and will kick back on after it cools for a few minutes. Try researching that and you might find some troubleshooting tips. Hope that helps.

[@edmalts]

Tom Wigren ok. I just tested the rv and a/c running on low fan setting. Shutting down on high setting. Capacitor?

[@TomandJulieMineExploring]

When you are in fan mode, without the compressor running, does the fan work on high and low speeds? If the fan runs on both speeds and the compressor runs I think it is some other issue besides the capacitors.

[@edmalts]

Tom Wigren correct tom. Fan runs on both high and low on fan only position.

[@TomandJulieMineExploring]

www.rvforum.net/SMF_forum/index.php?topic=83630.0 Here is a link to a forum that might help you.

[@wallycass2780]

I am wondering if you have ever heard of this problem: My Dometic AC runs fine for 25 minutes and then cycles on and off every few minutes meanwhile the RV is getting hotter and hotter inside. My theory is that the compressor is getting got and shutting down to cool down but what would be causing it to get hot I wonder. fins are clean and ducting clear. Could something else electrical be the problem? Any idea Tom?

[@TomandJulieMineExploring]

It is possible that the compressor is overheating and the thermal shutoff is cutting off power. This can be caused by low charge(refrigerant), low voltage(can be caused by the capacitors) or many other things like wiring, and pressure switches if your unit has them. One other possibility is that if you have redirected a vent towards the thermostat it could be satisfying the thermostat's demands while not cooling the cabin. Since the capacitors are the cheapest and easiest thing to replace I would do that first to eliminate them as the problem. Start and run caps. Hope this helps and good luck!

[@wallycass2780]

@@TomandJulieMineExploring Thanks for your help and I will try your suggestions.

[@rubenmora7863]

What capacity is the black capacitor?

[@TomandJulieMineExploring]

Hi Ruben. Sorry, I don't have that information at this time. If you are replacing your capacitors, get the same type that are currently in your unit.