Hello all, I have a 94 Cherokee and the aux fan wont kick on, even with the ac on. I have jumpered the fan to the battery so I know the fan is fine, also I've been doing some reading and I came across this, http://www.lunghd.com/Tech_Articles/..._Diagnosis.htm
Now for my question, it appears that this jeep has two cooling fan relays, one in the PDC and the other coming off of the wiring harness on the drivers side, but my jeep is missing the one on the drivers side also it's an odd 6 pin relay as seen in my attachment, Now where would I find one of these I've looked for more documentation on the matter and cant really find anything (don't know what sort of amps,volts, etc that I would need), also I followed the steps in testing from the link and when I jumped pins 1 and 4 together (in the PDC) it produced sparks, I'm assuming their talking about the relay in the PDC because the other has 6 pins not 5, but nonetheless how should I be testing these connections? Thanks

 

Does ac compressor kick on and fan dont ?

 

Older xjs have the one on fender yours wont , try unplugging coolant temp sensor yet fan should come on with key in run position.

 

Hello I'm not sure if the ac compressor pops on or not, would it make an audiable noise or how would I go about seeing? also @freegdr mine has the one on the fender and in the PDC (I just took the above picture today) but I have not tried unplugging the coolant temp sensor yet, I'm assuming the one in the front, on the thermo housing?

 

One on fender might be egr mine has two on fender no pdc here, and yes unplug that sensor see if fan runs then .

 

Well I just unplugged the sensor (with ac on then off) and the aux fan does not kick on

 

Switch ac relay with fan relay see if it comes on ?

 

Well I switched the relays, and still a no go, where would you guys suggest I look now? The fuse in the PDC looks good, and according to my owners manual there aren't any fuses that connect to the fan in the kickpanel fuse box, so I'm at a lose here

 

Grab a test light and test all fuses anyway. Make sure ignition keys in run position.

 

Thiis links not year correct for yours but the testing still the same.....http://www.lunghd.com/Tech_Articles/..._Diagnosis.htm

 

That's the Data Link Connector. If you had an OBDI code reader you would connect it to this.

 

I have tested the connections according to this site (by jumping across terminals 1 and 4) it just produced sparks, it should also be noted that my relay is not marked 1,2,3,4,5 it's marked 30,85,87a,87,86 so what terminals would I jump on my setup,I jumped terms 30 and 87 together (since their in the same place as 1 and 4) and it just produced sparks, Thanks

 

well guys I was hoping I could report back here with good news but no, I changed the thermostat, got a fan shroud (idiot that had it before me removed it) and flushed the cooling system (though I was being rushed through the job and it was pretty dirty,so I think another cleaning is in order) but something very odd I've noticed from driving around town in these hot temperatures I can let the gauge get up to 230+ and the fan will not kick on, BUT if I turn off the vehicle an let it sit for 2 minutes then turn it back on the fan will kick on right away and stay on till temps fall below 210, now I know I'm reposting to an older thread but what would cause this erratic behavior? could the previous owner have replaced it with a non cherokee fan and that's screwing things up? I really don't know, any help would be appreciated, Thanks

 

Well your sending unit for your temp gauge is on the back of the head so it will read higher than the thermostat sensor. Your thermostat sensor may be a bit off as well. The reason it kicks on after it sits for a minute is all fans are off with no air movement and it actually makes it hotter under the hood finally kicking on the sensor to tell the aux fan to run. May just need to change the thermostat housing sensor. Get a MOPAR one. Or you could just wire the fan to a switch, or both.

 

Yes I had thought of this as well, I have replaced the sensor (not a mopar one, but a new one nonetheless) and I still have the same symptoms I should also note that changing out the thermostat and replacing the fan shroud helped immensely but I still get the slow creeping overheating issue, I also don't get the efan to kick on with the defrost or ac on. I'm going to be doing a really good flush with hot water here in a few days (still seeing gunk in the filler neck) so I'll report back hopefully with some good news