Air conditioner not blowing out vents
 

1995 g-30 cargo van
Blower motor went out, replaced with new unit motor now spins but doesn't blow air out of the vents. I can open the door (not sure what it's called) that is just inside van and fan blows air there but just doesn't seem to shift to the vents, no manual so don't know where it's supposed to shift from floor to A/C vents:confused:. Any help on troubleshooting this would be great since i really don't want to rip the dash off to find this fault THANKS Jim

Look under the dash at the a/c unit. Is there vacuum hoses to it? I'd suggest run a new temporary vacuum hose from the accumulator pot under the hood towards firewall with a hose to the control valve. You could have a bad vacuum supply hose, see if that works, if not, probably the valve. Also with the hose off the control valve, and running, see if you can feel vacuum.

Tanks for the reply, All vacuum lines have been checked and connected. My understanding is that if vacuum lines were disconnected or bad that the havc would default to defrost is this true or false? Where is the control valve your talking about? Is it the one that controls the door or? As I'm sure your aware of finding these things under these vans sucks :cool: So location would helps tons Thanks again Jim


P.S. if the control valve is bad could it just be forced to stay open so wife won't die in the Calif heat till this weekend for me to repair

Thats correct. I have a 1970 Olds that has vacuum control, it is doing the same thing as you describe, all air is out the floorboards. I am 99% sure your control valve is issue, however to help verify I'd suggest pull a temp vacuum hose to rule that issue out.

You'd have to manually open it, but it can be done

the vacuum hoses are probably deteriorated and dry rotted. you will have to run new hose to the T on the back of the throttle body. I did this a while ago, super duper easy once you remove the doghouse. What is happening in your case is the hose that connects the vacuum reservoir(the round black toilet bowl thing mounted to the underside of the hood) is either missing, broken or disconnected. Without that reservoir the air only blows to the base of the windshield.

Do you think the fan is airlocked...blocked off? Fan motor rotation is correct? Does it move lots of air when you open the access door?