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[Flintstone]

G'day folks, I'm after some info on the electric radiator fan on my 2003 WJ.

A few days ago after stopping the engine I heard the electric fan running. I waited but it didn't shut off, temperature was normal so I pulled the fuse. It didn't reset anything as when I re-fitted the fuse the fan came on again. It does this whether the engine is warm or cold.

So, could it be the switch or is there a relay somewhere? My local garage have two sets of software but in both cases there's no wiring diagram.

Thanks in advance.

(If anyone knows where I can get a Haynes manual or similar I'm all ears).

[Dutch]

Google is your friend 

A radiator temperature-sensing switch activates the fan relay at 198 degrees F turns the fan on and controls its operation. Make sure the key is off. Switching relays is the fastest way to check for a bad relay when possible. A Jeep has more than one relay that are the same (go by the relay number on the top or side of the relay) in the fuse box on the driver's side fenderwell. Remove a known good relay and swap it with the radiator fan relay. Operate the vehicle and check the operation of the unit replaced. If the unit works with the fan relay it proves that the relay is not the problem. Test the relay using jumper wires and a voltmeter. Connect one jumper wire from the battery positive terminal to the relay positive terminal. Connect the second jumper wire from the negative terminal of the battery to the negative terminal of the relay. When the negative wire is attached to the relay, the relay should have an audible click as it activates. If the relay fails to click, move the jumper wires to the second set of terminals in the event the wrong terminals were being used. If the relay fails to click it is bad. Check the radiator fan switch if the relay proves to be good. If the fan switch is good, check the radiator fan by using the jumper wires from the battery to the electrical connection on the radiator fan to wire it directly to the battery. If it fails to operate the fan is bad.

[scrw]

[scrw]

Fan relay, easy to cut the plastic under the headlight to get at it

[Flintstone]

Dutch,

Thanks for that. I should have said I already swopped the 40amp fuse over. I didn't see a relay marked 'Fan' in the fuse box.


Scrw,

I did see mention on a 'merkin site of the relay being under the headlamp with talk of getting at it wait a "box cutter" (Stanley knife to us Brits). Not being absolutely certain it was for my model I filed it away under 'Useful To know' but shall now unfile it and have a look.

By the way, putting a relay under a headlight? Really?

Shall report back next week after I get home and have a fiddle.