1999 JGC Overheating

[NDH]

I have a JGC 4.0, the fan does not come on when needed ie during traffic etc.
Not sure how to test the fan to determine if this is the problem or not. Can I jump the fan to the battery to see if it works? How do I manage to do this?

I am new to the forum but would apresiate any help possible.
NDH

[JDPascal]

Welcome to the forum!!

First thing is give the fan blades a flip to see if the motor is free to turn or seized.

There is a fuse and a relay (I think) for the fan. They should be listed in the owners manual.

Use a test lite or a multimeter(prefered) to check for power at the fuse and at the motor...there is also a sensor somewhere on the rad that tells the computer to run the fan motor. The sensor could be bad............. or the computer.

Last resort is jumping power to the motor.

I'll see if I can find the wiring diagram for this for ya. Might take a day though.

JD

[NDH]

Thanks for taking the time to reply.

The fan blades move easy.
Checked the fuse under the hood and there is power to it, the fuse looks OK, changed out with another and still does not work. Tried to test for power where the fan plugs in and found none.

Unsure about the sensor however. From other posts it seems that the is a 'radiator fan control sensor' hidden behind the light somewhere. Do you have to purchase these from the dealer?

If you can find a wiring diagram that would be great.

Again thanks for taking the time.
NDH

[mikris]

I had the same problem with mine. The is a fan switch/relay located on the passenger side of the vehicle behind the head light assembly. I had to remove the battery and light assembly to access mine. As for the part, at the time of purchase it was a dealer only item.

[JDPascal]

Hey NDH

I found a wiring diagram.

PM me your email address from the bottom left of this message and I'll send it to ya (JPEG format)

JD

[JDPascal]

hey NDH -- Check your PM's (that's not PMS though)


JD

[NDH]

Hey JD
Traced the wiring to the cooling fan relay. Would not have found it without the diagram.
The relay is below the right (passenger) light, very difficult to get to. Replaced this (close to $100 from the stealership) and the fan is now working - cold air at last.

Thanks for your help
NDH