I did all the test to find out why my fan controlled by the sensor in the head is not working. I unplugged the relay and made sure all the prongs had voltage. I put 12 volts to the fan it it comes on and runs fine. I cut the wire that goes to the switch in the head and it it comes on and works fine. My question is does that mean my fan switch is bad? If the relay was bad would the fan still come on when i grounded the switch wire?

 

If you grounded the sensor wire from the pass side head and the fan comes on, you have a bad ground switch in the head. Replace it.

 

true, another way to test is if your car is equpped with ac and u turn the ac on it should kick the fan on, if you look at a schematic there are 3 triggers for the fan, the switch in the head, the ac being on, and the third is like an ac pressure switch or something.

 

today i grounded the thermal switch wire to the frame and once the car got warm to about 200 the fan doesnt cut on eve nthough the connector gets 12 volts to the fan it will only work while the motor is cold or not running?

 

grounding the switch wire tells the fan to kick on so it doesnt matter if your engine just started the fan should have kicked on, if you say the connector for the fan is getting 12v but the fan isnt functioning then your fan motor most likely went bad

 

what i was saying was if i grouned to the frame while it wasnt running the fan would cut on once the motor started to give out heat the fan would stop running put a new fan motor on it today and it works great.