My radiator fan will not turn on by itself and the car is getting 110C. However, it will turn on to high speed if I switch on the A/C.

My tuner told me that the problem does not lie in the temp sensor or the fan relays or the fans itself. He tested the voltage of the temp sensor and it appears to be OK. He also tested the relay by closing the 4 relays manually and the fan will respond to each of the relay showing slow, medium and high speed. Is this the correct way of testing the relays?

He believes that the relays are not receiving signals from the ECU. Is there a way to test this?

Please assist. Many thanks.

 

If the temp sensor is sending s signal and the relay is not reciving the signal then I would say its in the ECU but that is a very uncommon problem. I would check for voltage going into the relay when the motor is at running temp or warmer, just dont let it get to warm. If it is the ECU you can prob find one in the parts for sell,.

Good luck.

 

Also check to se if you have voltage going into the ECU, you could have a broken conductor.

 

no good

 

Thanks, SVT Squasher.