Classic symptom of a bad fan clutch.

That's not a proper test of a fan clutch. A failing fan clutch will still spin when the temp goes up. It just doesn't lock up enough and freewheels so that it's not pulling as much air as it should.

The proper way to test a fan clutch is to remove it from the vehicle, turn the spring 180° from its original position to lock the clutch, reinstall it on the vehicle and watch the temperature gauge to see if it fixes the problem. If so, you then take the clutch back off and replace it.

A fan clutch costs about $35 to $40 and involves 8 bolts, albeit on a pulley that can make it a bit of a pain in the *** to figure out how to remove. And while those symptoms are not a 100% indication of the cause, in this case it's usually the culprit. To me, if I'm taking the stupid thing off anyway, I feel like it's worth the $40 gamble to just go ahead and replace it given how likely it's the source of the problem. Bothering to test it first just usually feels like a waste of time.

The other acceptable (but less effective) way to test a fan clutch is to insert a piece of rolled up newspaper or magazine into the fan while the truck is running to see if you can stop it. It should chew the crap out of the paper and not stop. If it does stop, it's definitely bad. But even that is not a 100% reliable test, since the clutch could be not completely freewheeling but not completely locking up either.

Personally, I would start by replacing that clutch and THEN trying to figure out the electric fan. The electric fan is just there as a helper to the mechanical fan. In most cases the mechanical fan should be able to keep the engine within the normal range on its own, assuming the clutch is working.

 

shaky - you were correct, the newspaper test was worthless. An entire newspaper wound a tight as I could was chewed up faster than I feed it in the fan - and this was <1 min after starting the engine. Well - put a new clutch in anyway. No change - electric fan still does not come on. I did confirm the ground is good in the wire harness connector back to the battery.


Now that I have a more repeatable drive cycle, it seems that the only way to get the temp to rise is with ambient 90+, driven (something to build heat in the engine), idle 5-10 min, A/C on. Take one of those items away and it stabilizes in the ~230 range. No more lights or near red zone (only once with the old clutch) - but in the last stress test the IR gun said 260 and the gauge read ~240. Should the electric fan be on? If not - what the frack does it take?

 

Old thread but hoping someone checks in to help.
We replaced the a/c compressor and took the jeep to the shop for the a/c service. After he filled it, he called and told me my fan isn't coming on with my a/c and it is supposed to. He recommended, because of mileage and pain in the rear chasing down a wire or possible issue with the PCM, to install a toggle switch. My fan comes on like clockwork when my jeep gets to roughly 210. Stays on a few and kicks off again.

I read some other threads where people are saying the systems were changed in 00 and 01 and the electric fan doesn't come on with the a/c but comes on when the a/c builds to a certain pressure.

is this true? Should we go ahead and install a toggle switch or chase down the problem?
thanks in advance! 🫶

 

your 2000s fan does not activate with the ac temps must hit 220°f ac has no effect

 

ok so now that I've run it on my mail route with the ac on, the temp of the jeep goes above 210. It's never done that before. Just slightly. Maybe 213.

 

And the fan comes on at around 210 and stays on. I'm just nervous about it. I don't need to mess anything up. Thanks for your reply!