djb383

I believe the fan clutch was referenced in post #3 by excess650.

djb383

Man Law - don't start a overheating thread until after the radiator, water pump, t-stat and fan clutch have been replaced and known to be good. Just kidding.

drake7

i know that it is not the clutch fan because it works fine. if we put the ac on the e-fan still doesnt come on.

jretzky

The clutch fan does all the cooling until the engine reaches a certain temp. You can replace the cluth fan if it isn't working. The electrical fan is run by several things the relay, relay fuse link, sensor, and the fan diode assembly. Several things turn on the e-fan... the ac, ecu, and the radiator hitting 180* plus degrees. If your Jeep has both...you need both. My friend has a 2001 4. L and it has only a cluth fan and thats all it needs.
After all my searching today the electric fan relay is on the inside of the left fender and the electric fan sensor is on the left side of the radiator above the radiator hose. The fan diode is in the wiring harness same as the relay. Well I am talking about a search I did for 89 Cherokee 4.L.
The thermostat had a lot to do with over heating of my car.

Thanks to everyone that posted today. John

tiwvr1

Hense the reason Y I said almost everyone. I Just really hate people throwing there hard earned money into fixing something, when there is something else that is causing the problem.

I understand his Efan is not working, and it is a problem, But it shouldnt over heat with out it on, unless the outside temp is really high. The clutch fan should be more then enough to cool it, unless there is a restriction in the radiator, or plugged fins. I just see to many threads where people replaced this that and the other thing, and they are still having problems with the original symptom.

djb383

How can u tell if the fan clutch works fine? Do u know it's age? Their performance begins to deteriorate gradually beginning the day they are installed. Definitely need to address the efan issue if using a/c.

djb383

When running a/c, u need the efan. This time of year, all cooling system components need to be in top notch condition. One of my favorites is....I'm overheating, I replaced the radiator cap, what else could it be?

tiwvr1

Just thought of something for the OP. Is the fan shroud there, and in good shape? I know it wont help with the e fan, but it will cause overheat condition if the fan is pulling hot air in.

Yeah love it when people post stuff like the rad cap thing. Just like, "My check engine light is on, do you know why"

djb383

^^+1 on the fan shroud.

stereodesigner

Stop all the messing around and just run a power wire to a seperate relay (from autozone) then to a switch turn on the efan whenever you want

cdawall

Not when your driving down the freeway at idle yes you do. However his jeep should not overheat with a good working clutch fan. He needs to replace it just because it spins doesn't mean its working correctly.

drake7

well we know when we had the fan hooked up to the switch and we turned it on that it wouldnt over heat. and the fan just simply isnt coming on. not if we put the ac on, not if the temp gets over the 218 or whatever that is. we even switched computers out with another jeep from the junkyard and it still didnt work.

btownxj

here its for a 92 4.0 it says the ecm turns it on at 190 or when the ac is selected on.

jretzky

Well just for your info... my 1989 Cherokee Laredo 4.L was over heating.
The first thing I did was run a hot wire from the battery and it turned out the E-fan motor was shot.
But then the E-fan still didn't work so I grounded the e-fan sensor (in the left side of the radiator above the lower radiator hose) with the new fan and the fan came on.
So I replaced the radiator electric fan sensor ($22.)
At 210 * the fan still didn't kick on so I replaced the e-fan relay ($10.) on the inside of the left fender. Still no luck.
I took the wire harness and the relay and separated it from the fender and turned over the plug it had grease and dirt in the plug for the relay. Cleaned it up and attached it back to the fender and started up the Jeep and the e-fan runs now.

You never know what the problems going to be.

John

Techprimus

Though it has been said I want to put in my 2 cents because I was having the overheating issue not even a month ago, which I don't anymore.

At first I thought it was the electric fan, which I hotwired to the battery and found out did not work AT ALL.

So I replaced the fan, and wired in a switch so I could choose when to turn it on and how long to have it on.

THIS DID NOTHING AT ALL TO MY TEMP.

Here is what actually fixed the problem: new thermostat and radiator flush. If you have the original thermostat, it is supposed to open at 190 degrees F. But if it is old, it may be opening at higher temps or only opening partially. I replaced mine with a brand new one that opens at 180 degrees, and gave it a flush and some new coolant. Now instead of running at 210 degrees or above, it runs at 190 even when idle in traffic.

And guess what? That electric fan still does absolutely not a darn thing to the temps LOL.