I've checked the fan, OK. I changed the relay. I changed the temp sensor. Radiator fan won't turn on. If I disconnect the temp sensor the fan will run when the engine runs but will not shut off. If I plug the sensor back in while it is running the fan will keep running till the engine cools down. But it will not start back up again till I unplug the sensor. Any body expierince this before?

My dad's '89 Cutlas Ciera exhibited strange fan behavior like this once. It turned out to be the main computer.

One check you can try... the fan should stay on all the time when the A/C is on... it should only run when needed with A/C off.


I've checked the fan, OK. I changed the relay. I changed the temp sensor. Radiator fan won't turn on. If I disconnect the temp sensor the fan will run when the engine runs but will not shut off. If I plug the sensor back in while it is running the fan will keep running till the engine cools down. But it will not start back up again till I unplug the sensor. Any body expierince this before?