Been having some issues with my WJ overheating... I think I have narrowed it down to the fan not operating ( electric fan.... ). The fan itself appears to work when i connect it to a 12v power source, the temperature gauge appears to work correctly, making me think the temperature sender works. My older cherokee had TWO senders , but i can only find one on the newer engine. I can not find a fan relay anywhere in the vehicle, I checked the PDC and the fuse panel , everything appears to be in order , the 40 amp fan fuse has power and continuity through the fuse with the key on.... I am running out of things i can check without a service manual or a wiring diagram...

Does anyone else have a useful idea?

I have joined a WJ forum , just waiting to be approved my a moderator before i can post...

I am away tomorrow , but I will be back on friday.

Thanks bombers!

 

A JEEP?? .....





Whatsa matter ?? - diesel too $$$ .......

 

I would let the Jeep run. Once it gets to temp see if the harness to the fan get power. Thats a simple way to tell

 

I did that , no dice...

and yes , I am too cheap to pay 1.20 for diesel... that , and my truck is non operational...

 

Sounds like a bad fan control module!

 

Any luck on the JEEP site?

 

FCM? this is not a VW , it's a mopar product

I was away (on the road) for a few days , so i have not gotten to post on the jeepsunlimited yet.

I stopped by the dodge dealer this aft, they told me to check behind the front bumper cover for the fan relay , i have the front end torn apart all the way back to the radiator , and i can't find a relay anywhere...

What I have found, in the plug going to the fan, with the key off , one wire has 36 ohms of resistance to ground , the other has nothing... with the engine running cold , the ground wire goes up to 176 ohms of resistance, and the second wire in the plug , reads nothing, with the engine past operating temperature, the ground remains at 176 ohms of resistance , and the second wire comes alive with 14.2 volts. Out of curiosity , i started checking various spots on the body for continuity to ground , it would appear that no matter where i check , there is very high resistance to ground.

Right now I think I am up against a very bad ground, I'm going to wait for things to cool down , and then start checking/cleaning grounds and see where that takes me...


P.S. - windmills anyone? :

 

That's considered the fan control module/relay. It sits up behind the bumper on the passenger side. Now say your sorry!

 

You work at a dodge dealer too?

I need to purchase more tools... The fan control relay is PWM, and I currently do not have a way to test and see if that is working correctly , so, I am going to assume it is , and purchase a new relay. I took apart the fan connector , and individually connected the wires , and the fan worked for about ten minutes , then the voltage started slowly dropping and the engine started overheating. The relay also got VERY hot at this point , hot enough that I would not touch it.

I am going to order a new relay and install it on wednesday when I get home and hope that fixes it.

 

I have access to All-Data and I've had my share of Jeeps. The oldest was a '42 Ford GPW.