Two weeks ago I thought I had a defective cooling fan. I sent my newly acquired Ford Racing cooling fan (3 months old) back to Ford Racing and they sent me out a new one.

Today I received an email from Ford Racing saying that their engineers looked at the fan I have sent them, and after testing found the fan working just fine (both speeds). Later that day I receive the brand new fan, and sure enough after the install, it fails to start.

Once again I checked the relays, fuses, wiring and the fan plug. I even checked the underside of the fuse box to make sure there are no burn marks as one member recommended. Everything looks fine. I am completely stuck guys, I do not even know where to begin other than putting it in a shop, which sucks, for a simple cooling fan issue.

 

does the fan come on if you turn the a/c on? have you checked the thermo switch to see if its working?

 

No it does not turn on with ac either. What is a thermo switch, the thermostat ? I replaced the thermostat 3 months ago as well, but I can check it again if that's what you are referring to.

 

The fans operate according to temps of the engine plus they kick on high when the a/c is turned on. Need to locate those sensors and see if they are functioning. Cannot direct you on their location at this time.

 

Fan comes on based on cylinder head temp. Does your instrument cluster temperature gauge appear to work?

 

Yes, the gauge works just fine. And to followup on AzPete's post, I believe our cars only have one sensor, water temperature sensor in the thermostat housing in a v6, and a Cylinder head temperature sensor in the v8.

 

if the fan doesn't come on with the a/c i would say it's not the thermo switch! have you checked all your fuses and the relay

 

Yeah, checked them today for the third time. Was hoping for a miracle. This is the most frustrating problem I've had with the car

 

Have you used a volt meter to check for power at any of the relays and plugs? That is the only way to really verify what is happening.

As a temporary fix to drive the car, you could wire the fans to a manual switch that you turn on when the car is running. That would also verify the fans work.

 

Pull the relays out and bench test them.