I have a 2001 S-10 ZR2 P/U. With the heater control selector in the feet position I still get air blowing out of the upper section. This happens wherever I have the selector switch. Is the switch bad and how hard is it to replace. Thanks Tery

Do you get heat from the front vents when you select front vents?

I know most heat/air systems are vacuum controlled, and the default damper setting is the defrost/floor vent. If you have a vacuum leak somewhere it will not allow the dampers to open and close thereby allowing just air from the default defrost/floor vents.

I have the same problem with my S-10, but have not found the vacuum leak yet. Also after a few months of this my system quit altogether. I think I have a vacuum leak somewhere AND either my control panel module or blower has went out.

Hope this helps a little. Maybe a real expert can provide a more detailed explanation.

Robert

Do you get heat from the front vents when you select front vents?

I know most heat/air systems are vacuum controlled, and the default damper setting is the defrost/floor vent. If you have a vacuum leak somewhere it will not allow the dampers to open and close thereby allowing just air from the default defrost/floor vents.

I have the same problem with my S-10, but have not found the vacuum leak yet. Also after a few months of this my system quit altogether. I think I have a vacuum leak somewhere AND either my control panel module or blower has went out.

Hope this helps a little. Maybe a real expert can provide a more detailed explanation.

Robert

Yes I have heat coming out of all the vents.

Yes I have heat coming out of all the vents.

the vacume seal is most likely cracked, its a bi*ch to get to, behind the dash back by the firewall, it opens and shuts the "door" that controlls where the air can go, my old truck does it, only i cant defrost my windsheild in the michigan winter

Look for a bad vacuum line going to the vacuum ball in the engine compartment.