I'm wondering why you said this part. Don't all jeeps come standard with a mechanical clutch fan? There are two fans standard in Cherokee's with AC, the mechanical clutch fan coming off the block and the aux cooling fan connected with the AC system.

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The mechanical clutch fan is driven off of the engine... you can test to see if it's going out by heating the jeep up to running temp, and then killing the engine. Try spinning the clutch fan by hand. If it spins freely, the clutch is worn out and you'll want to replace it. It should have resistance on it at temp when you try to spin it by hand (Obviously only try this with the engine turned off).

If your AC/aux fan is not engaging at ALL, (either when the engine is at temp or when you manually turn on the air conditioning), then yes, check your power to the fan first. Do a direct connect from the fan to the battery and see if it manually powers that way first.

If it does power on when connected to the battery, you have one of two things that might be wrong: 1) your AC is out of refrigerant and is not engaging the fan correctly (not as likely) or 2) your fan relay is bad and needs to be replaced. I suppose there IS the third option, that the fan itself is dead... you'll know that when directly powering it to the battery though

The fan relay is an easy fix. Never had to worry about the AC going out before, but I've read it enough times here to know that it's a causal factor potentially.

Once you get the fan working correctly when AC is engaged (either by replacing the relay or the fan itself (or both)), if it still doesn't engage when engine temps hit 220*, you'll want to replace the coolant temperature sending unit that should be on your rad and plugs into the wiring harness for the electric fan.

I had to do all of this only a month ago on my 1990 Cherokee after routinely running at a constant 225* no matter what... so school of hard knocks, here.

But check the mechanical fan clutch. It's about a $60 part, but probably worth replacing if you've never changed it. How many miles again on the XJ?

If you DO replace the mech. fan clutch... it's easier to pull the radiator at the same time. I tried it the hard way and it just wasnt' fun. Of course, I ended up replacing my rad, too, so that made it easy to get to then :P

Best of luck to you

 

I am thinking that a cooling overhaul might be in order. If I replace the radiator, hoses, fan clutch, water pump & sensor (already replaced thermostat) I figure I should nip it in the bud.

 

I just replaced all that on my 99 last week and now it runs at exactly 210 at all times (except while warming up to that temp). Mine's got 138k miles so I figured a new cooling system would help it last another 130k anyways, besides as long as your in there might as well fix/upgrade it all right? I'd recommend a CSF 3-row all metal radiator, got mine from DPG offroad. The only hard part I ran into was getting the bolts off the water pump pulley, use a pry bar if you don't have air tools.

 

I would test your electric fan to make sure it is ok.

 

Best bet, take the mech. fan out and convert to two electric fans and hard wire one in that way it is always blowing then another to a switch that way if you are getting a lil too hot you can flip that switch and bam it will start to cool it down, This is the type of set up i am running, But i usely just remove the fan that is to a switch cause it dont get too hot around here, but i put it back and hook it up when i go on highway drives or when i go wheeling, i am running about 200-210 in the temp range so its perfect. Good luck keep us posted.

 

Yeah i guess i was more tired then i though last night? ive even stuck my fan in the radiator with a bad motor and tranny mount before? what was i thinking? but still if he/she is driving and its staying cool and when he/she is sitting then its going to be the fan cause its not drawing air through the radiator like its suppose to... most will have alot of play in them when not turning... i dont know what i was thinking... but the AC fan isnt going to have anything to do with the engine over heating... if its coming on or not... unless the jeeps different and it wired in to kick in to help the mechanical fan which i doubt... that would be stupid i think... if its not coming on then that would be a whole different problem... but not one to keep u off the road... u can drive it with out AC... just not overheating... to cover the AC part with the fan not working thats already been told... Fan, freon sensor,freon its self, switch, grounds, everything ive ever worked on AC wise its always been the freon being low and NEVER anything else... but thats just my experiance...

 

I am taking tomorrow off work to change the radiator, water pump, fan clutch if needed and hoses, sensor etc.. Is this job going to kill me or is it doable in a driveway? I figure if I got the crank position sensor out and in, then I can do it!

 

It is very dooable and easy,just take your time so you do not put a hole in your new radiator.

 

I did a couple tests today. I let it heat up to 24 or so while idling and the AC on. I can hear the compressor kicking on & off so I am sure the AC is at least engaging. It's really hot here today but I could still feel cool air. The electric fan never kicked on. I unplugged the fan and hooked it to a 12 volt battery and it fired right up. So is it a fuse, switch or that sensor on the thermostat housing?

I then turned the Jeep off and spun the mechanical fan freely even though the temp was over 230-240. I thought it would have resistance at that temp? Maybe I don't have to replace the radiator if it is those 2 things?

 

It sounds like the sensor,you were going to change it anyway,see if it helps. I replace a sensor in a t-bird once and nothing worked because it was not compatible with that model,I changed it out and all was fine,most of these systems are the same.

 

well u can take te radiator out... put all new fluids in it when you put it back in and change the mech fan... then when the fan doesnt work and you spent all that money on coolant... you can drain it and start over... PS the top part of the grill where the hood latches has to come off to get the radiator out... well at least mine did after i spent forever trying not to... wait yours is a 89 like mine... yeah its coming off... i got m radiator with only 5000 miles off ebay shipped for $10... lol... now if the fan works with power then stand outside with the hood up and cut the AC on... you can actually see if the clutch on the compressor kicks in or not... its the outer part of the pulley... if it does or doesnt come back and let us know...

 

It's a 1996. The clutch on the compressor is coming on it appears. Tomorrow I will replace everything so there is no "Do-over"..

 

I/m about an hour into it and man it is a job! I have to figure out how to get all the lines unattached now. The tranny lines look like a bear. Just isn't any room in this thing!!!!!

 

Get your radiator hoses out of the way,the top trany line just unscrews,the bottom one is a plastic clip that you squeeze together ,the top radiator support is held in by 10mm bolts,and 11mm bolts that are under the header that saxs jeep on it,it is very simple.

 

Have to run to the store. The new radiator has female threads for the top and bottom lines and the old one had male threads on the top and a pressed in steel line about 3" on the bottom going to one of those plastic compression clips of some sort. I hope they have something to rig it up!