I have a pontiac grand prix 98. Its fan is not working so the temperature goes up. I changed the radiator and I also tried air bleeding, changing relay, fuse, temperature sensor on the top of the engine. When I unplug the temperature sensor, fan is working.
Please help me with this. What else should I try to make fan working?
The best way is running an On Board Diagnostic. To check if the new temperature sensor is working, use an ohmmeter and take the reading from the pin. It should give you some reading in ohms or kilo ohms. Normally, when the coolant is hot the resistance of the sensor is low and the resistance is high when the coolant temperature is low. Disconnecting the temperature sensor sends a signal of 0 or open which translate to high temperature in electronic logic. So, the problem can be trace from temperature sensor--- to ECM --- fan relays ..