Help with heater/ac
 

I need help trying to make my Jimmy blow hot air only. I have an ac but it is disconnected. When I turn on the switch to the blower it blows hot air out of the defrosters and floor vents, but still blows cold air outside air out the ac vents. The switch was an addition that was there when I purchased the Jimmy. It's my daily driver for the time being, and it has gotten very cold down here in TX. Any advice would be greatly appreciated.
:confused:

Sounds like your partition in the heater box is not closing off the a/c part. May have to disassemble it and see if the cables are closing the passages off. You should only get defrost when its on defrost and heater will blow out the bottom and a/c vents when its on heater. Might also check the vacuum line to the damper on the passenger side vent in the cab. Good luck, Jeff.

This is a rather common problem with the AC diverter boxes. More than likely the door that diverts the air flow is broken at the hinge shaft so that the shaft moves but the door does not. The diverter box is easy to change out and my suggestion would be to buy a new one and change it out after you verify that it is bad.

Jim

Have to agree on the diverter box.

Mine did the same thing.

Try the following two links, they only list back to 1980. But give them a call, I purchased one through one of these two. Just can't remember which one.

http://www.gmpartsdirect.com

http://www.partszoneonline.com

Thank you for the help. Now I know where to look.