I have a 04 Suburban, 137000 miles. The heat on the drivers side blows cold air no matter what the temp is set at. It also blows from the center vents only. No defrost also.

The passenger blows hot air like it is supposed to.
I have searched and found the reset idea and tried it, didn't work.

Where is thee valve, switches that control the heat to the drivers side.
Any help would be appreciated. It is getting cold here in New jersey

Thanks
Tom

 

Its the a/c actuators. There's 4 of them in the front. One of them controls the zone (floor or dash vents), another controls the temp. I "believe" the one that controls the temp for the passenger side is above the passengers left foot (just above the edge of the trans hump. You will have to remove the black plastic cover underneath there to get to it. (The inside-most screw is a son-of-a-bitch to put it mildly).

The actuator is a small black plastic box basically. They are expensive as hell (autozone is like $130 for one). A guy on ebay sells them for 39.00 and has good reviews). Im about to buy one myself for same vehicle.

 

There are other online parts suppliers that sell them for good prices. They will also sell you A/C Delco parts at half the price of the dealer. Try them like RockAuto Auto Parts.

 

pacemakertom and Norbit if you do the replacement yourself, try and take a few pictures of the process and we can use it for a how too DIY...