Having a cooling problem on really hot days with the a/c on. I was going down the list of things. When does the electric fan kick on? Is it supposed to kick on when the a/c compressor does? I had it at 210 with the a/c on and no electric fan activity. I wasn't getting anywhere with my search on this subject so sorry if its a common question.

 

the fan should come on with ac check the connection,fuses, and relays. If all these are good connect the fan directly to battery then you will know if it is bad.

 

It would help to know what year.

I have a 1990 and the electric fan comes on as soon as I turn on the AC. I can't remember it getting hot and comming on without the AC on.

 

It's a 2000. I swapped the fan and ASD relays briefly to see what would happen. It didn't help anything.

 

does ur ac work?

 

2000 the fan will come on at about 218 ,AND THE FAN WILL NOT COME ON WHEN YOU TURN THE A/C ON.Then it will kick off at 210 i think temps are just rough temps.

 

To check your electric fan you can pull the plug off the temp. sensor on the water neck but it will set off the CEL when you unplug it your fan should fire up. then just reset the CEL.

 

lol read his post

 

Those are some high temps for the electric fan to kick on. Makes me want to wire it up with a manual switch. Maybe ditch both the stock fans and get two electric fans. Ill check it today with the unplugging of the temp. sensor. I didn't think i was going to get away that easy with solving the overheating problem.

 

Let me know if I can help more.

 

how hot are you getting the 4l runs at 210 this is normal operating temp for this engine on 2000+cherokee the fan is only suppose to come on around 218 again this is normal and will not come on with the ac like the older models

 

It doesn't really overheat totally. It gets to about 220 at the most during the middle of the day (100 degree Florida heat) at stop lights with the a/c on after long drives. The problem is that when it gets to 220 i have zero oil pressure at idle. So, i'm trying to keep it cool so i don't loose all my oil pressure.

 

you can go to the dealership and have it reprogramed to come on with the AC. it should be free too.

many people have done this before

 

try running different oil and changing your fan clutch but thats not a super high temp for that weather

 

My money says the oil pressure gauge and/or sending unit are bad. When oil pressure actually goes to zero, you hear some really horrible sounds/noises, just prior to the engine seizing up/locking down.

In the triple digit weather we've had, stuck in traffic, a/c on, have momentarily seen 230F on the ScanGauge and not even a flicker out of the idiot light.