How it Works: Understanding the Mechanics of Your Truck's Air Conditioning System

[@DIYSEMI]

DIY SEMI, TRUCKING AND MORE • 59 seconds ago For great fuel discounts with no fuel card required, watch this video! kzbin.info/www/bejne/gpulZoxsZdVkp6s

[@bigmike9060]

AC is not hard but you need gauges, scale, and refrigerant. I didn't just learn to fix it on KZbin, I've learned from HVAC guys and trusted mechanics. One other thing. A condenser is a very vital component with the system. If you put the guages on the system and start it up you will see the low pressure side at 30-50 psi and high side pressure of 150-250. If your high side is always up at the 200 plus range you have an evaporator that is struggling to dissipate heat. One way to determine this is while your hooked up to the system and it's running . Spray a garden hose on the condenser. You should see the high side drop down to the 150ish pressure. Prolonged higher pressure causes a higher head pressure on the pump and can lead to a failure of the pump. Just some ideas for maintaining the system and why it does what it does. Oh and humidity and ambient air temp play a key roll as well

[@vicpetrishak7705]

Want to mention if inlet and outlet heater core coolant lines are hot the cooling system will not override the heating system . Install ball valves on the engine block to the heater core coolant lines . 6/17/23

[@DIYSEMI]

I have a video how to do that

[@alexplus3]

Thank you for sharing information which is very useful

[@RealMC77]

Very informative video. I will change out all of my components during in-frame overhaul…truck has over 1.4 million miles on dash.

[@firoznagra4927]

Very helpful information Thanks

[@LauraBruno33]

Important information and knowledgeable on air conditioning, another great video!

[@DIYSEMI]

Thanks again!

[@LauraBruno33]

@@DIYSEMI your welcome. Have a good weekend.

[@jajimenez12214]

Awesome content

[@DIYSEMI]

thanks

[@bigmike9060]

Another thing that causes poor AC is the exterior of the expansion cable gets covered with dirt and oil. The expansion cable works based on the heat from outside to very the refrigerant flow. There is a point if enough oil covers it long enough it will plug the diaphragm hole

[@DIYSEMI]

Good tip, also if it looks covered in oi!, that can be a leak right there.

[@danielbrown8602]

COOL video!

[@carlt8976]

Great content, excellent video. It's all very helpful!

[@DIYSEMI]

Glad you think so!

[@abdirahmanhirsi4958]

Hello sir i have an issue on my truck freightliner century 2007 when ever I try on the A/C OR HEAT I HEAR SOME SOUND LIKE A CLICK ON MY A/ C COMPRESSOR VERY OFTEN ANY IDEA

[@joeyalbergo]

Can i lubricate that clutch or bearing on the compressor wheel? Or anything to do to maintain it?

[@DIYSEMI]

No

[@alexplus3]

Can you do close-ups of all the components that you are naming

[@DIYSEMI]

Sure

[@jayw8768]

Do you have a video on the problem you had with that power supply wire? Had an issue with mine a yr ago and Freightliner “fixed it”. It lasted exactly 13 mo where their warranty doesn’t cover the repair now and it’s doing the same thing again. I can’t find where they spliced a replacement plug into it but that’s what they said they did.

[@DIYSEMI]

What you would want to do to start is turn on the a.c..truck running.. then unplug the plug up by the compressor. Use a multimeter to test the plug for power and ground from the truck. If you have power and ground but the compressor still doesn't work, the wires could be broken inside the compressor itself. That has happened to me. That is assuming your refrigerant charge isn't empty or too low to start the compressor. It needs to be almost empty for that to happen. Sometimes that problem will be intermittent, where it will "sometimes" work...that's a real pain. You will need to do that test when it is acting up, also wiggle the wires around while you are testing the plug. I would start there.

[@jayw8768]

DIY SEMI yes it was intermittent same as last year until it stopped completely. Same as last year. I know newer components can fail but compressor is only 14 mo old too. You know typical shop with ac. Instead of diag a problem first thing they say is oh you need a new compressor or like the TA we can evacuate and recharge it.... Neither of which solves other issues lol. It has Freon. No leaks. High and low pressure switches replaced when the compressor was along with the can. Running a jumper wire in low pressure switch plug and direct briefly from where the relay is neither will cause the compressor to come on. Tells me it’s not getting power again from the wire or plug. I don’t have a multimeter in here just a simple test light with ground wire type that I use for fuse checks. Would that tell on that wire ?

[@DIYSEMI]

@@jayw8768 test light will work, won't tell the voltage...but at least you know you have power. Don't feel bad these a.c. problems are extremely common. Especially in freightliner because they ride so rough it just hammers the wiring. Let me tell you why I started doing all this video stuff. In 2016 I took this truck in for the bunk a.c. not working. I came out with a $3500 bill. It worked 4 days then quit again. Dealer through their hands up up and said I dunno. I came home, bought a pump and set of gauges, bought the parts on line to fix it myself and rebuilt the whole a.c. system front to back, lines and all for about 1500. A.c. work is a bit of a scam. Like you said. Get the part number off the compressor. I bet you can find it online for about $125. If you believe its a bad compressor, I will tell you how to change it yourself and save a ton of money. Most shops do a poor job on a.c. work. Ohhh...and the $500 sanden compressor they sell you at freightliner is really no better anymore than a Chinese knockoff. So you may as well buy the Chinese one and save $400 . Once you can replace it yourself, who cares if it only lasts 2 years...still cheaper

[@jayw8768]

DIY SEMI lol my bunk ac doesn’t work even when the ac works but I have a tripac. I’m in the same boat as u. Even looked at the Schneider gliders when I bought my Columbia glider used from a dealer. Mines an old grand isle express glider but it had a tripac so hadn’t been idled to death. I think my compressor should be good. Was replaced last July in a shops wrong assessment of the power issue. Cost $335 at freightliner for the part. Wasn’t too horrible. Great content btw. I need to start doing some of the investing you talk about.

[@markmarroquin667]

Hey i got a problem on my fl centuary where the bunk isnt getting any cool air from the fans any suggestions on what it may be?

[@zxcorpionz]

I have a 2009 pro star , every time a hit a bump on the road my fan clutch comes on witj AC ON . It doez not do it witj AC ON. I replaced high temp sensor 4 weeks ago . What do you all think it is? I'm betting it is the loe temp sensor

[@LOUDsigh]

Interesting but now I'm scared to try and fix my problem

[@georgewilson1184]

I think this guy is a OOs for Schneider National Carriers Green Bay Wisconsin

[@DIYSEMI]

nope, just bought a truck off their lot

[@mohala1271]

My ac air conditioning pushing so weak any recommendations plz

[@isaiahnelson6387]

My bunk blows not cold but everything else works fine

[@ellstackeradventures]

Need that ac