2003 Z71 Suburban. Has malfunctioning air conditioner compressor that needs replacement. Makes grinding noise in right front when on. Too costly to repair for the value of this vehicle. Can I safely run the heating system and defroster without having the air conditioning compressor engage? Would like to take this vehicle on a long road trip in the winter and will want to run my heating system and defroster. I understand that some vehicles use the compressor to remove moisture out of the air when running the defroster. Help!

 

Welcome to the forum. I think you can pull the fuse and/or the relay that controls the power to the a/c compressor clutch. If the bearings are gone in the pulley, then you will need to remove the belt

 

want to run my heating system and defroster. I understand that some vehicles use the compressor to remove moisture out of the air when running the defroster. Help!

You are correct and your compressor is engaged when the defrost selection is on. If you disconnect as the op suggested, it will be no problem to use the heat and defrost. If your defrost is not working well on high heat, you might try lowering the temperature, JMHO and good luck. A/C Compressor, drier, expansion valve, system flush and freon should be available for just under $1,000.00. Your vehicle is worth more than that !!!!!!!
David g.

 

I'm curious what you were told the repair would cost, unless its a clunker it shouldn't be bad enough to say its not worth it.

 

The system will only turn on the compressor if it's over 40° outside. Below that, the computer keeps the compressor off.

However, if you want to be double-dog sure of the compressor not running, remove the belt. The compressor has its own belt.

IIRC, I think it cost me about $400 for a compressor/clutch replacement. If you do go that route, make sure you replace the tensioner pulley, too. After the repair, I had the tensioner pulley seize, snapping the belt, on a mid-summer road trip in 95°+ weather. I was not happy.