Radiator Fan only turns on when a/c is on?

Plastic

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So I finally got around to replacing the drive belt, pretty easy process. But I went for a short drive afterwards and within 5 miles noticed my coolant light on, proceed to look at the temp gauge.... Which is pegged at 250 plus degrees. :(

So I pull over, shut the car off, pop the hood, and it doesn't seem to be that hot. So I loosen the coolant cap expecting it might shoot antifreeze everywhere, but it only burps up a little once. I limp it back home and think maybe the fan isn't running so I turn my ac on and the car immediately cools down to normal.

Bottom line the PCM isn't telling the fan to turn on after a certain temp.

I can only guess that it's the temperature sending unit just happened to go bad on the same day I swapped the belt?

Anyone have any other ideas?

For now I took out the ac relays and fuses so when the car gets hot in traffic I turn the ac switch on and the fan turns on without kicking the ac clutch on.
 

Luisv

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You have two fan relays. High Speed and low speed. On the 2002 they are identical. If you want to check, just swap them and see what happens. They are at the front end of the power distribution box on the drivers side.

Other thing you can do is disconnect the fan and check the harness. When the car is on and at temperature, the low side of the harness will go to 12V. Since the high speed comes on I would say the fan is fan, but you never know. If you get voltage on the harness, the the low speed on the motor is bad. (I don't know how the motor is configured)

I just had the same issue, the fan had to get replaced. Good news.... I take about 20 min to swap out.
 

rollymohan

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plug in a scanner and go to functional test then put the cooling fans on ,do high and low speeds if they both works then the system is good and you now need to monitor the temperatures while the engine is running and see if the sensor is reporting and the pcm is commanding the fans to go on.
 
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Plastic

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Thanks for the replies, I ended up ordering a roe fan kit that will override the fans to turn on at a certain temp. I also ordered a scan tool......so both things should take care of it
 

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