Re: Radiator fan module problem
The light (that looks like a radiator) indicates one of a few failures. In the case you are dealing with, the light is an indication (probably) that the Fan Module is not communicating with the PTCM.
Here is how it works:
The PTCM sends pulses to the FCM to tell it how fast to run the fan, and as a "ping" to make sure the FCM is still alive.
That is....
The PTCM 'pings' the FCM from time to time, the FCM "pings" back. If the PTCM sees this ping, it knows all is ok. If it does NOT get the ping back, it lights the light.
On the OTHER hand, if the FCM looses the pings from the PTCM, it turns the fan on full speed as an emergency mode to keep the engine cool. It does this, since, if it is not getting the pulses from the PTCM, it has no way of knowing how much 'fan' is needed.
Either the FCM is bad, power to the FCM has failed, or the bidirectional wire between the FCM and PTCM is open. But if the line was open, the FCM would run the fan at full speed. So, it sure looks to ME like the FCM is bad OR the 50 amp fuse is bad.