no heat ac out upper vents

rich85730 · Post by **rich85730** » Wed Oct 19, 2005 11:52 am

i have a 1988 s10 blazer and air stoped comeing out of upper vents, now only comes out lower vents i replaced a/c control switch didnt help??

barch97 · Post by **barch97** » Wed Oct 19, 2005 12:05 pm

how's your transmission?

bubaloo1983 · Post by **bubaloo1983** » Wed Oct 19, 2005 12:51 pm

that would be the hvac problem. someone will post the link i cant remember where it is. i have the same trouble 2 times so far :S

F9K9 · Post by **F9K9** » Wed Oct 19, 2005 2:13 pm

HERE and welcome to the forum

I wouldn't think that it applies to an '88 but, this explains what our problem is.

Rusty · Post by **Rusty** » Wed Oct 19, 2005 4:14 pm

I'll have to go check my '89 (I have a S-10 Blazer too) but I'm fairly certain that the system is quite different and I think the HVAC controls and transfer case vacuum switch are isolated from each other. At least I know they are on mine. This sounds more like a loose vacuum line somewhere.

Post by **HenryJ** » Wed Oct 19, 2005 4:52 pm

Check the vacuum pot right near the accelerator pedal.
Also , if you just replaced the control, check to make sure that the red tab did not slip out iof the retaining bracket. That happens pretty easily when trying to put it back in place.