Overheating - what triggers the cooling fans to be turned on and at what temp?
My 08 MKX is overheating. I tested both fans direct to 12V and they both work.
So I was pretty sure it was the Fan Control Module that was bad, but after a little more testing, I am not so sure anymore.
Please feel free to chime in if you have the answer to any of the below questions.
1- To help further test, does anyone know at what temp the fans are suppose to come on?
2- And what triggers - or sends power to the Fan Control Module to turn on the fans? (is it the coolant temp sensor)? The main connector that plugs into the FCM has 3 wires (12v + Ground + a small white wire). I tested the small white wire for power (with a test light) and nothing, I tested it for power all the way up to 206 degrees F (then I shut the car off as I didn’t want it to overheat) 3- Does anyone know when and how that small white wire from the FCM should have power - if that’s what triggers the fans to turn on?
4- With my OBDII scanner, I can monitor the ect (engine coolant temp) and the temp seems accurate, would this confirm that my ect sensor is not the fault here?
2- And what triggers - or sends power to the Fan Control Module to turn on the fans? (is it the coolant temp sensor)? The main connector that plugs into the FCM has 3 wires (12v + Ground + a small white wire). I tested the small white wire for power (with a test light) and nothing, I tested it for power all the way up to 206 degrees F (then I shut the car off as I didn’t want it to overheat) 3- Does anyone know when and how that small white wire from the FCM should have power - if that’s what triggers the fans to turn on?
4- With my OBDII scanner, I can monitor the ect (engine coolant temp) and the temp seems accurate, would this confirm that my ect sensor is not the fault here?