A/C Clutch always engaged when the control switch isn't on OFF
 

I have an issue that is causing my A/C clutch on the condensor to be engaged at all times even when the heat is on. Noticed it from condensation from the cat heat shield. So what is wrong with it? A switch, relay, the actually clutch?

See your owner's manual so you understand the control settings that affect the compressor.

Thanks for the info, but the a/c clutch is still engaged even when the switch is on Panel or Floor... which the manual says it should not be running.

Any other thoughts?

Check the clutch gap with the system off to see if the clutch is mechanically jammed in the engaged position.

The clutch is not engaged when the control switch is in the off position... Spins freely. So I am kind of at a loss here.

Sounds to me then that you have a bad switch. Is there a salvage yard near by that you could test out with a used one first?

Thought of that, but the switch still works in the form of diverting air flow to the panel vents and floor vents correctly... so I am not sure it has to do with the switch. Maybe a relay that is stuck on, and is only getting 12 volts in every position but off... just speculation.

J

on most vehicles, air flow to vents and floor is controlled by a cable while a/c is electrical. I will check mine to confirm

If the AC Clutch disengages when the control switch is in the off position then the contacts in the switch are bad. I noticed on the ’05 models they have a separate AC switch. You could probably add a switch and bypass the control if changing it out isn’t what you want to do.
I was thinking of modifying my ’03 like this:

http://i50.photobucket.com/albums/f3...F150/ACMod.jpg

After looking at the diagram again, there is also the possibility that the Brown/Orange wire is shorting to the Violet wire so that the blower relay power is diverted to the clutch engage circuit.


Edit:

The signal that energizes the AC clutch relay is controlled by the PCM so some further troubleshooting would be necessary. Check the voltage on the Vio wire coming out of the control switch while going through the positions to verify if it is good or bad first.

Did you ever get this problem fixed? Mine is a 97 model 4.2 and it is doing the same thing.