I got this truck several months ago and have had issues with the a/c always running in any fan position except OFF. The clutch kicks in any time the fan switch is turned on.

Another issue is the defrost not blowing hard and the front dash vents always on. In order to use the defrost I have to run the ac on high even with heat on just to clean the windshield. When it is hot outside that is undesirable. I could unplug the a/c pump, but why not change the way it works? I want separate heat and a/c any ideas?

The truck had one of the vacuum lines disconnected and the other one hooked up directly that go inside. I found a truck with the vac line on it and hooked mine up right, as far as I know, which actually changed the way it shifts in overdrive and the idle is better. The defrost vent is still stuck apparently because only low flow out of them in any position.

 

I think you have more than one problem.....

Your fan switch should go two directions, one side is for a/c, the other is for not. The compressor will run in some positions regardless of which way you turn the fan ****. (anything involved defrost)

All of your vents are vacuum powered, if you put the selector switch on defrost, and are still getting air out the dash vents, either a door in the heater box isn't doing its job, an actuator is bad, or the control head itself has an issue.

 

My a/c works in any fan position.

 

If you put your vents on floor, and turn the fan switch to the non-a/c side, does the compressor still run? if it does, the control head has an issue.

Or..... if you turn the fan OFF, does the compressor still run??