Jeep Cooling Fan Override Switch Install

Having cooling issues out on the trail? In this video I will show you how to install a cooling fan override switch. Today we will be installing on the factory electric fan in a Jeep Cherokee XJ. I will show you how to install from start to finish. If you have any questions that the video does not cover, make sure to leave them below.
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Parts Used in This Video:
Rocker Fan Switch: www.amazon.com...
40 Amp Relay: www.amazon.com...
14 Gauge Wire: www.amazon.com...
Electrical Spade Connectors: www.amazon.com...
Music used in this video:
Last Second by Silent Partner

[@jonoxthomascito6516]

Best mod I’ve seen since I got my jeep 4 months ago

[@masterveil7660]

Just bought an XJ as a daily driver an don’t know anything about XJs You have been lots of help with this video 🙏

[@omni7phaty]

I have run across your videos before and found them very well produced and informative. Today I subscribed because even though your jeep is newer than my daughter's 96 XJ you have very informative how to videos. Thank you!

[@jasonbodi503]

Just used this video for my 92 and it made it SOOOO easy. Works perfectly. Great for me because my XJ is a 92 but the motor was swapped to a 98 and there's communication issues from the computer to the fan because of it. My fan works but the Computer isn't telling it to turn on. This bypass is nice!

[@nomadadventures-tv]

I have a 98 too and Im thinking my computer has communication issues too. Im installing this today. Wish me luck. Thanks for the video. Great direction.

[@donlum9128]

At auto zone for 8 bucks you can buy a relay wire plug in makes it cleaner install. Good video

[@butchhall3647]

Thanks man watching this has helped me find whats going to fix my heat soak problems.

[@butchhall3647]

@floridaBoy i did exactly what you said , i replace injectors and out fuel sheild and block sheild also 100% fixed the problem.

[@renaissancemilo9676]

Glad I stumbled across your channel man! I'll definitely be doing this cheap, and practical mod.

[@stevenm7566]

Another well done video. Clear instructions and easy to follow. Thanks

[@georgemullin7772]

Great video vary informative

[@trevorthomas6043]

This mod is a good idea helping with heat soak issues with the 4.0 engine.I hope this doesn’t fry the ecm

[@OutJeeping]

It shouldn't, any backfeed goes to the factory fan relay, not straight to the ECU.

[@sketchyrides8086]

I just finished doing this to my xj. Awesome tutorial thanks a lot for making this video!

[@MrMrsregor]

i would install a *3 way switch* OFF (for deep water crossings) Automatic (for road driving) ON (for fully loaded, 4x4, climbing steep mountain, hot days)

[@OutJeeping]

Great idea!

[@qdoggyrufruf]

why would you want off?

[@willkelly86]

Why not just add a diode and switch from the existing relay coming off of the PDC? This would cut out the need to mount additional relays, fully loaded wiring or fuses and better protect the PCM from back current. I think this would be a much simpler and more elegant solution to a problem.

[@bryanmelillo26]

S-ro Sorcxisto was thinking the same thing just run it from the splice and add a ground and that’s it

[@prometheusthefirethief3479]

@@bryanmelillo26@So-ro Sorcxisto worse case scenerio is we burn out some relays. The current never reaches the computer the computer controls the relays

[@mortenjohansen4120]

I tried that on my 2000. It gave a CEL

[@ThehagNfriends]

What's the part numbers on that switch and relay.

[@davepenprase]

Would it have been easier to use the existing cooling fan relay and just groung the low current side??!!

[@dissociativecat7495]

I pulled the rear window defogger board and switch out at a junkyard and used it for the fan, the board itself is basically a latch relay and the switch is a momentary contact the fan can only be turned on in Accy or run and is off at start up. I once made the mistake of using an aftermarket temperature sensor and it ran 40° hotter according to the gauge I purchased a mopar sensor and the gauge read 195° like it should

[@OutJeeping]

Hmm yeah that ain't good. But good thing thermostats are still mechanically operated but yeah the ecu wouldn't be turning on the electric fan at the right time with a bad sensor, or telling you when you should override the fan to turn it on.

[@mortenjohansen4120]

Will this circuit cause backfeeding voltage and CEL on a 2000XJ?

[@Kentuckygoatman]

Also want to know but on 1998 xj.

[@Moonshinedave1]

Thanks for the video. Something to think about, if you go to your fuse box, you will probably find a spare power tab that is only hot when the ignition is on ( I haven't done this with my XJ, but have with other vehicles, I am sure the XJ fuse box has spares too) use that power for the switch going to the relay so that when you turn the ignition switch off the fan goes off (even if you forget to turn the fan switch off). Of course, you have to ask yourself, do I want to be able to run the fan with the ignition off, or do I want to be sure I don't forget to turn the fan off and run the battery dead accidently? I did this on a an old truck when I installed aftermarket fog lights (thanks to a neighbor, I didn't run the battery dead).

[@essay-ezofficial4462]

Which wire did he splice into the cigarette adaptor neg or pos?

[@TheCooltrejo]

Helped me out a lot.

[@EadsGPTs]

Thanks bro this helped me allot

[@jasoncarmichael1635]

Great video! Thanks for making this so painless!

[@nellaob4229]

Great Video!! What radiator do you have in this jeep? How many Rows in the radiator?

[@Silkforge]

Great video!!

[@Motorcycle_Man]

Will this put the fan on high or low speed

[@game_ender1]

Hooked up everything as it supposed to be to a two prong toggle switch and to a four prong relay. Hot wire coming from my fan goes to 87, 30 to inline fuse to battery, 86 to ground and 85 to toggle switch, every ground has been cleaned, tighten properly and double checked and nothing. Switch works and checked relay for continuity and is all good. I even got two different relay just to make sure it wasn't it but I got nothing. I know it gotta be something so stupidly simple but I can't see it. Any input?

[@OutJeeping]

85 is ground and 86 is from switch.

[@Jmanwit]

Well, I may be slow. I thought I followed the instructions to the T, but it appears that the fan isn't activating upon turning on the switch. The lights on the LED work, but no dice on the fan.

[@danielcarney6193]

Should probably note or edit the video that you need to install a Diode where you tapped into the circuit to the fan... it needs to go between where you tapped into the power side of the fan wire and the ECM, this way you will not back feed the ECM and throw codes... Also I would suggest using different color wires for ground and wrapping all wires in some form of wire loom

[@OutJeeping]

Yup i'm well aware of the CEL but didn't notice at first due to already having the light on. Also this was my friends Jeep and he's to cheap to want to wire it neater.

[@danielcarney6193]

@@OutJeeping its always difficult to get the friends to do the job right..... I tend to not work on their vehicles... cause it always fails later and they blame you....

[@jonoxthomascito6516]

New to jeeps how do you get the wires through the fire wall ? You drill a hole or something?is there a hole already ?

[@OutJeeping]

I usually pop a hole through a wire harness grommet that is already in the fire wall. It can be done on either side.

[@jonoxthomascito6516]

@@OutJeeping thanks

[@acrock21]

my camaro has some overheating on hot days and when i run it hard ... its the lt1 im thinking about putting a switch like this in it.

[@ibrajuhani6572]

But i think two wires (positive wire )sharing the same value will make overload on that wire!?

[@OutJeeping]

@ibrajuhani6572 It won't, the fan is what draws the amperage. That won't change no matter how many wires of the same power source lead to it.

[@TheDisBeat]

I just jumped my relay to run continuously while vehicle is running

[@OutJeeping]

That is another good option as well.

[@mitchellwebb3183]

I have a 1999 wj I could never get the fan to come on. I tried your video and worked great. I used a 3 prong light up switch instead. I only needed it to light up when it was on.

[@40Spec]

The DisBeat how did you wire it to run when the vehicle is on?

[@3m4zY]

How did you jump it?

[@warpedcheeto9322]

Very helpful video, I didn't know jackshit about wiring ,but I aced it thanks to you. 10/10 would recommend 👍

[@hamudified7663]

Is 14 guage wire good enough to run two 80watts fans? I am planning to do this in R50 Pathfinder

[@davidvenegasramirez6001]

Ay yo, I want to do this for my Mishimoto fan. Initially, I wired the fan up for an auxiliary setup, but want to delete my mechanical fan now. But I need to wire a switch into the car so that it stays on all the time until I turn off the switch. What changes do I need to make? Please help me on this!

[@brianplevelich7178]

Nice video, it helped me. But 2 questions. The black wire coming off the OEM fan is ground ? And, my switch only has 3.spades on back. I used the one from the relay. But were do I hook the other up to. ? One is labeled 2, other is 7.. I assume one is ground & one is power. ?

[@OutJeeping]

Yup, black wire off the fan is ground. Hard to say what the pins are because every switch is different. Some are 2 way, 3 way, some have lights in the switch. But if I were you I would look up the diagram for your switch and for basics you need a positive feed to the switch and positive return back to the relay.

[@davidperkins1367]

Thanks.

[@davidperkins1367]

If switch is left on will it run batt. Down?

[@OutJeeping]

It will, it's essentially directly wired so it will not automatically shut off.

[@Deezy29]

Hey man great video,I have a switch think it’s the same one, did you have trouble with that switch contacting the bezel?

[@OutJeeping]

I did, unfortunately with these larger aftermarket switches you will have to notch out the bezel for the switch. Otherwise on Ebay, they do make factory style replacement switches that are customizable.

[@thedon7528]

Can u send the link to the parts you bought

[@jcbRedhawk09]

How does the electrical circuit change if I just want to use a simple toggle switch instead of the one used in the video.?

[@OutJeeping]

It would be even more simple, just need a fused power to the switch and a wire from the other side of the switch to the relay.

[@dissociativecat7495]

@@OutJeeping you should still use a relay a switch may not be able to handle the load . Contacts have and make and break rating so be careful it may be rated at 30 amp make and only capable of breaking the at load of 5 amps

[@OutJeeping]

@@dissociativecat7495 Yup still gotta run a relay like I said. Not worth running the risk of burning down the jeep from a simple mistake lol.

[@corwinmallonee4319]

I'm confused I thought that the purpose of putting a relay in place for thus kind of mod was so that you don't backfeed your electrical system, but you don't disconnect your factory fan power and reroute it in anyway that prevents power from the switch back feeding through the factory system

[@OutJeeping]

Adding a relay is to prevent all the power for the override switch to go through that and not switch itself. The back feed power should just go to the factory relay for the fan. I wanted to keep the factory option in case I'm not paying attention to the temp gauge but also have the luxury to switching it on whenever I feel like it to monitor temps closely.

[@corwinmallonee4319]

@@OutJeeping yes but i feel that your 4 pin relay wiring job dosnt really prevent a possible back feed into the factory system. I feel that the only way to truly prevent a back feed of some sort is to go with a 5 pin relay. i cant share a picture sadly but after i did a lot more research i did find a pretty decent wiring diagram for a 5 pin relay system

[@corwinmallonee4319]

@CABANA J i suppose that would work in theory

[@DBNEBMUSICGROUP]

Do you have a garage close to nyc? Man I would love to work out my xj with you! I be checkin all you vids for real thanks

[@OutJeeping]

Nah only in Wisconsin lol

[@ogj5]

Great video- this is exactly what I need. Do you have a list/links to all the parts you used to do this?

[@OutJeeping]

I just updated the description with links.

[@ogj5]

@@OutJeeping you are awesome thanks!!!!!!!!!!

[@Jeepfreak1999]

I'm running into the over heating due to Florida weather is there anyway you can post a list of items needed.

[@OutJeeping]

40amp relay, a 12 volt switch of you're choice, 14 gauge wire, and some spade connectors.

[@ozekinci]

Hi Could you please put links to all wires, switch etc that you used for this project?

[@OutJeeping]

I just updated the description with links.

[@MikeXJ98]

Great video dude! Now I have the confidence to do it on my own. Just one question. Where did you ground off the two ground wires for the switch? I assume somewhere metal under the dash? Thanks!

[@OutJeeping]

I used a bolt the holds in the dash right under the switch panel

[@MikeXJ98]

@OutJeeping I just got my switch in yesterday with no problems. Thanks for a well-detailed video! You have a new sub, can’t wait to see more XJ tutorials! Keep up the good work.

[@vwclub3]

Doesnt this trip the temp gauge into not working wile switch is on

[@hardstepps]

@@vwclub3 No because you are just adding redundancy. You aren't bypassing the OEM temp sensor that sends the command to the pcm which kicks the fan on. You're adding this switch after that system.

[@solomonlopez3514]

Where did you get those tiny little fender flares on the Xj in the very beginning of the video. Ive seen them on quite a few xj builds, but I cant find what they are.

[@OutJeeping]

They actually are not flares, it's just thick bed liner.

[@jmillie94]

What happens if it’s in override mode and te jeep decides to send power as well?

[@OutJeeping]

I haven't had an issue, It should be fine when the Jeep gives power as well. When the Jeep doesn't, I believe it just back feeds the factory fan relay on the output side, which isn't a big deal. Some say it may cause an engine light so a diode install on the factory fan supply wire should fix that.

[@willballadaresgb]

followed your instructions but my power outlet fuse blows out any ideas on how to fix it from going out?

[@OutJeeping]

Seems like the switch might not be hooked up right, what type of switch did you install?

[@SpaceCoast_]

Did you have any "hot soak" issues causing "vapor lock"? maybe know someone who has and said that this can also help with that? thanks for the vid!

[@OutJeeping]

My own jeep had it and yes running the fan after it is off will help prevent heat soak from occurring.

[@SpaceCoast_]

OutJeeping Thanks man!

[@willkelly86]

You could add a timer relay to keep the fan running for a few minutes after the ignition is off. This would better vents the engine compartment permit hot soak issues.

[@seanstackz3683]

Where does the double ground wire to hook to rocker switch magically come from???

[@OutJeeping]

I forget where I pulled it from but it can be tapped from the 12V power outlets or grounded on the dash bolt that is located under the switch panel.

[@seanstackz3683]

@@OutJeeping thanks! I figured it out. You are my favorite jeep guy; most accurate & concise. I've learned a shit ton from all your videos.

[@rohitter7878]

Great video can I use just a simple switch with no LEDS? One that only has the power and a ground on the switch?

[@OutJeeping]

Yup the little led light is just for prefrence

[@rohitter7878]

Perfect im going to give this a try. Have you done the extended idle?

[@adamswaz4878]

@@rohitter7878 i just did extended idle the other day

[@rohitter7878]

@@adamswaz4878 any instructions on how you did it?

[@adamswaz4878]

Rogelio Cerrillo message me on Instagram @adamswaz and I will get back to you with how I did it

[@BeardedJibaro]

I know this is a stupid question but where does the factory harness for the auxiliary fan connects to?

[@OutJeeping]

I believe it goes back to the fuse box to the factory relay for the fan.

[@BeardedJibaro]

@@OutJeeping imma have to go to the junk yard and see if I can find out lol

[@jaxonmarkey9081]

Can you turn it off whenever too? Mine stays on after the jeep is off

[@OutJeeping]

Yes, it is no longer controlled only with the ignition so you can turn it on and off with the vehicle off as well.

[@justjsse8917]

Anyone help me? Im using a 3 prong switch.. wired it up just like his but im stuck on the other 2 prongs on the switxh. 1992 xj

[@OutJeeping]

What type of 3 prong switch do you have? Does it have a light on it? Regardless of the switch, all switches need to have a + power going into it and a return going out, which in this case goes back to activate the relay.

[@mannyg7761]

Great vids bud, do you Instagram?

[@OutJeeping]

Yup, I got a link on my channel page.

[@DoubleB-87]

I wired this up but didn't add a diode. I left the fan on while at work and the battery died. I jumped it and now it won't idle unless I feather the gas and hold the brake. Any ideas what went wrong????? ...

[@OutJeeping]

Give it a few runs to get the ecu back up and reading the sensors properly

[@DoubleB-87]

I have since installed the inline diode, no change, had to ziptie the throttle so it will stay at idle. Swapping out IAC AND TBPS tomorrow. Could I have fried my ECU? Not throwing any codes

[@JameyCampbell_54]

Lol oh boy

[@jamieashmore4388]

What kind of switch did you use exactly?

[@OutJeeping]

I just updated the description with links.

[@marcoramirez4074]

Whats the amps that the switch had

[@OutJeeping]

I believe the switch could handle up to 20amps but I would always use a relay to prevent possible failures from overloading the switch.

[@stevenharden803]

Where did you get the cool fan switch?

[@OutJeeping]

Steven Harden Amazon or ebay

[@ProjectDanH]

I did this on my 01 XJ. It throws a CEL every time. It was annoying so I disconnected it.

[@stevenharden803]

Project Dan H that's too bad. I wonder if it'll throw a check engine light for every model and year of XJ

[@ProjectDanH]

Steven Harden not sure.. I would assume all obd2 would throw the code.. maybe 1995 and older would be ok

[@OutJeeping]

That's weird, mine and my buddies jeep are both 01 and it doesn't throw any codes.

[@ProjectDanH]

OutJeeping I'll plug it in again and see what specific code it is.

[@OutJeeping]

A simple diode for the positive wire to the fan on the factory wiring side would fix the cel.

[@TheCooltrejo]

Where can I get the switch and the relay??

[@OutJeeping]

Any auto parts store for the relay or find them both on Amazon.

[@jackedsports4114]

I’m your 3,745th subscriber. Do I get a prize? Lol

[@OutJeeping]

My mom made some cookies, want one?

[@jackedsports4114]

It’ll probably be stale by the time it ships 😢

[@danhambrick6331]

Thanks for ruining the video...lol...

[@charliemullendore8473]

What gauge wire did you use?

[@OutJeeping]

I think I used 14 guage

[@charliemullendore8473]

Thanks Austin got my fan wired up now, and I’m awful at wiring lol so your video helped a lot

[@Elskrat88]

This didn't give you a CEL by any chance did it??

[@OutJeeping]

Hasn't on mine but on some peoples it has, it can easily be fixed with a diode.

[@Elskrat88]

@@OutJeeping haha not to inclined on how I would go about setting that up

[@OutJeeping]

@@Elskrat88 A diode allows power to trail only one way so by splicing that in it wont give power back to the original relay when the override is on. Therefore the ecu wont detect anything different

[@Elskrat88]

Really great to know thanks for the help and great videos

[@adamswaz4878]

@@OutJeeping isnt that the point of installing a switch that has LED(iode)

[@homerobo2705]

The rocker switch doesn't quite fit in the bezel.😏

[@OutJeeping]

It's a little tight but there are other options to go for a switch.

[@michaelzimmerman5114]

How do I do this to my renix ?

[@OutJeeping]

Should be pretty much the same but maybe having the switch in a different location

[@williamwarner3982]

Weather proofing. You will be redoing it in 2 years.

[@OutJeeping]

I agree, but my friend is lazy and didn't want to buy loom

[@williamwarner3982]

@@OutJeeping hehe. Ok. Solder and heat shrink

[@brianmarshall8616]

Confusing to a guy that ride the "short bus" to head start! Blasting through it like everyone is electrical specialist! If everyone else thinks this vodeo is easy to understand... Then I apologize for waisting 30 seconds of everyone's time!

[@OutJeeping]

I'm curious to know what sounded confusing? If you know the basic concepts on how a switch and relay work together it shouldn't be that hard to follow.

[@prometheusthefirethief3479]

My fan wont turn on when wired into the factory wiring like this, I cant figure out why. I have the AC on. Any help appreciated

[@OutJeeping]

I believe some year ecms dont have the electric fan turn on when the AC is on and only have it kick on when temperature rises over 215. That's the way my Jeep is and it's been like that even before I wired in the fan override.

[@prometheusthefirethief3479]

@@OutJeeping hey man thank you for your reply. I ended up opening up my JUNCTION box under the hood and i found a loose white wire coming from the ignition hot, going to the radiator fan relay was LOOSE. Guy that had it before me was jamming wires into this relay pannel likely what popped out the wire. Thanks again!

[@codemang87]

In my XJ(1998 sport) when my climate control is on defrost or defrost/floor it commands the fan to be on full time. Does this not work in all XJ's? Do you know which years it does or does not work on?