I have a 1989 mustang lx with a 4 cly,when i turn on the ac I smell a burning smell and I track it to the fan control switch under the dash, the large orange wire with a black stripe is the culprit, it is hot and when I remove the module the contact is burnt, I tried another module with the same result. The radiator fan runs, the ac clutch engages and produces cool air, but this wire gets red hot, could it be a short somewhere in the wiring? any help appreciated
thanks
Doug

 

I don't know the wiring schematic for the Fox off hand. However, I can tell that any smoke is BAD- as in stop what you're doing (you probably know that ).

Burning or smoking wires usually comes from trying to pull too much current through a particular size wire. Alternatively, it could mean that the wire is too small for the desired job. It is possible to have a cross short.

It is possible that the fan is trying to pull too much current (amperage) and is burning up the switch and wiring in between. Is the fan stock or aftermarket? If it's aftermarket- I would wire in a relay to protect the switch. I should also add that a worn out fan motor can also pull too much current.