I have the same usual problem of the heat not switching positions like from vent to defrost. seems to get some out of all three at the same time. Just got this ZR2 and have not checked that out yet. From what I read it might be the vacum lines. My question is if the control is not working could it also not be turning on the A/C? the PO said it worked last spring when he parked it for transmission failure. Would that keep the compressor frm engaging? It does nothing, not even click. thanks for any help.

 

The vent vacuum control is separate from the electrical function control....but could also be bad.
However if there is no pressure in the system the low pressure switch will prevent the compressor clutch from engaging. But also check to see if the clutch connector is connected. I guess you could jump the clutch switch to see if the clutch works or not and also if the compressor is locked-up or not. But would need to be careful in doing this...just a quick connection just to see if the compressor turns or not....or take to an AC shop and have them check the pressure.

 

Thanks Lanny. I will check that out. Never thought about the wire but I have not got into that project yet. Truck has been sitting awhile so I just take it one project at a time each weekend. Next will be the parking brake. When I push the lever The dog must not be engaging with the teeth to hold it and although it has new cables it does not hold brake wise anyway. Must need adjusting or new pads. Got the tranny fixed, fender flares and bumpers painted, engine bay cleaned up, buffed out the paint, interior detailed, new front wheel hubs done, new hood on last evening, etc. Takes time for sure. once again thanks and I will check that connector in the morning, might get lucky! However I did notice a lot of oily stuff on the compressor lines when I cleaned under the hood.