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Crestwood1001 11-07-2011 07:12 AM

2003 WJ Fan Failure
Buddy of mine drives a 2003 WJ 4.0, he's had overheating issues with it and it seems as though the fan does not kick in. We stood and watch it and you can hear the relay kick but the fan never starts spinning. Any common issues with this so I could help him out?

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JeepMe 11-07-2011 07:21 AM

Re: 2003 WJ Fan Failure
The common issue on these is the relay failing. But if you're hearing the relay flip, it might not be the issue. The first thing I would do would be to run a power wire to the fan to see if it spins when it gets 12V. If it does, break out the DMM and see why it's not getting voltage when required.

Crestwood1001 11-07-2011 07:59 AM

What's the location and coloring of the wires to look for?

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hoffmanestates 11-07-2011 08:30 AM

Re: 2003 WJ Fan Failure
i remember my cousin has to replace his fan every year as it fails on his 4.0 every dam year.... and everyyear we are replacing something due to over heating.. but he used barrs stop leak so thats his ongoing problem.....

Crestwood1001 11-07-2011 08:55 AM

Can anyone tell me the location of the power supply wires to the fan so I can test them?

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WJeeper 11-07-2011 11:36 AM

Re: 2003 WJ Fan Failure
This recently happened to me, and it was the relay, which is located underneath the passenger's side headlight and behind the bumper cover. A little tricky to get to without removing the bumper cover. Just be careful not to let the engine run too long or it will overheat and your radiotor will blow up like mine did.

Crestwood1001 11-07-2011 12:05 PM

Any tips for getting to the relay

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JeepMe 11-07-2011 12:34 PM

Re: 2003 WJ Fan Failure

Originally Posted by Crestwood1001 (Post 511077)
Any tips for getting to the relay

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You can either remove the front bumper cover and it's right there under the passenger headlight. The other option is to remove the passenger headlight, cut a hole in the plastic below the headlight, and get access that way.

There's an explanation on that shows that procedure.

2005JGC 11-07-2011 01:12 PM

Re: 2003 WJ Fan Failure
if you hear the relay that is not the relay you have... you cannot hear the one under the headlamp actuate, but if the relay is in the power distribution center it will be a style relay you hear closing. there was a short time on the wj body style while the fuse was in the PDC and iirc it was the later models. unplug the fan, take 2 jumper wires, have one go to the battery ground and get it on one of the pins in the fan connector (doesnt matter either way, typically black is ground but if you hook it up backwards it will just spin backwards). take the next wire to B+ at the battery to the other pin and if the fan comes on then you have another problem, if it doesnt you have a bad fan, replace it and retest.

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