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Discussion Starter #1
Cooling fan only works when I pull the 50 amp fuse and put it back in. Then the fan does not shut off till I turn the jeep off. It ove heated the other day because fan did not turn on. The relays, (the two in the fuse box under the hood) tested ok. I replaced the coolant sensor and the fan motor. I found another relay of some kind or a sensor under the battery box mounted on a brace when I pulled the bad radiator. Is this a fan relay also. Any help appreciated.
 

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Discussion Starter #2
Am I able to eliminate the fuse for the electric fan and go back to a clutch fan? I am still having a electrical problem that no one can locate so the electric fan turns on. The only thing that I can think of happening would be the check engine light would come on. Or is there a link in there somewhere where the computer would notice fan not working and tell the engine to do something crazy.
 

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That part in the picture is a air bag sensor.

Almost sounds like a bad relay. I’d have to look up the diagnostics in the service manual to see how to trouble shoot it.
I do know the KJ guys add and delete the mechanical fans so it might be possible if the shroud lines up correctly. Not sure if it’ll work right on a XK.

Isn’t there a resistor (or something like that ) on the fan shroud?


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Looks like the 4.7 has fan blades, might have all the parts to convert the 3.7. But I know the PCM controls a lot of the fan speed on the 3.7 don’t know if it would notice if it’s there or not.

So far the FSM is vague on testing the 3.7 electrical fan, there’s a lot about hydraulic fans which looks very different from my 3.7

Edit: all the FSM has is check 15 amp fuse junction block, 40 amp fuse in power distribution, if Test ok then go to relays.
There might something buried in the manual but I’ve not found it yet.
I know my radiator fan shroud has some kind of resistor in the wiring, not sure what the symptoms would be if that fails

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Thanks for the replies. I bought a new fan and shroud. It comes with a new resistor. I went to a local junk yard and there is a newer jeep liberty with a fan clutch style on it. I couldn't get it off the vehicle. I needed a bigger wrench. I think I'll go back and get it and try it. The water pump on my 3.7 is threaded for a mechanical fan. I replaced radiator yesterday with a new one. Haven't tried starting it yet to see what happens.
 

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The water pump is the same for the 3.7 & 4.7 engine.
Be careful to get all the air out of the cooling system. It likes to be a PITA if it can.

Still seems like could be a bad relay, but I understand wanting a more solid cooling fan.
The factory manual was disappointing, maybe later years have a better instructions for testing the electric fan.



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Thanks for the replies. Thanks for letting me know what that relay or sensor was. I left it in place. I did replace the radiator and added a mechanical fan clutch off a 3.7 jeep liberty that was in the junk yard. It was the only one with a mechanical fan out of 8 Libertys. So far after 60 miles, no overheating. The guage is in between 1/4 and 1/2. Doesn't seem to be leaking any fluid. The engine light has never came on. So maybe this thing is fixed. Will let you know.
 

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Looks like the 4.7 has fan blades, might have all the parts to convert the 3.7. But I know the PCM controls a lot of the fan speed on the 3.7 don’t know if it would notice if it’s there or not.

So far the FSM is vague on testing the 3.7 electrical fan, there’s a lot about hydraulic fans which looks very different from my 3.7

Edit: all the FSM has is check 15 amp fuse junction block, 40 amp fuse in power distribution, if Test ok then go to relays.
There might something buried in the manual but I’ve not found it yet.
I know my radiator fan shroud has some kind of resistor in the wiring, not sure what the symptoms would be if that fails

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my fan on on '06, with the 3.7, has stopped working too... where is the 15amp fuse and 40 amp fuse?? on the fuse panel diagrams I can't find anything that relates to the fan??? The only thing I've found is the hi and lo rad fan relays

is there a trick for removing the small "block" fuses?? they seem really "locked" in tighter than the usual blade fuse
 

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I am having the same cooling fan problem in my 2006 commander and also the ac quit working same time. put new fan and shroud and radiator it works when I pull 50 amp fuse and re install it but quits when shut off motor and restart. I need help with this anyone
 

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I am having the same cooling fan problem in my 2006 commander and also the ac quit working same time. put new fan and shroud and radiator it works when I pull 50 amp fuse and re install it but quits when shut off motor and restart. I need help with this anyone
You may want to become familiar with your junction block;

 
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