1987 GL Heater Control Failure

[colossal_monstrosity]

This post is in reference to a 1987 GL wagon, 1.8L, no air conditioning. The motor or whatever it is that moves the vents in the heater box between floor/vent/defrost/etc. no longer works, either due to a bad connection or wore out engine, or if it's vacuum fed (didn't look like it), then a bad vacuum line. I was just wondering if this had happened to anyone else or if it's a common problem, didn't see anything in the forums, and wanted to look for easy solution before tearing stuff apart. Thanks!

[WoodsWagon]

all the control equipment for the heater vents is down to the right of the accelerator pedal. look for white canisters, these are the vacuum actuators. They run the button functions. the heat range is operated by a cable, also down to the right of the accelerator. look for any broken parts and remember that the vacuum lines are often thin hard plastic (black) flex pipes.

[MilesFox]

there is a skinny hose that comes off the passenger strut tower that goes to the manifold. this controls all the heater and cruise functions.

 

if all your heat comes out of the dash vent only. look for that first. it plugs into a reducer from a fatter hose off the motor. it leads to a canister on the passenger side firewall, and tsmall rubber lineds to plastic ones into the body. check all that too.

 

the problem is most likely NOT the control unit on the instrument cluster

 

this is a fairly common problem in the sense that the hose gets knocked loose or forgot to be re-connected when servicing the car, and its easy to overlook.

[colossal_monstrosity]

Ok, I know exactly what hose you're talking about, I couldn't figure out what it went to (looked like nothing). Um, as for where it plugs onto the engine, there is so much vacuum crap there I cannot assemble it correctly without pics or another vehicle. It was a nightmare getting carb to work right on this car. So I guess my next question is, can I plug that hose into full vacuum or does it need to be down from a check valve or something?

[colossal_monstrosity]

Eh, don't even bother replying to my last thread, I went out and did just what you said, I just used a splicer and hooked it onto that full vacuum line that goes to my anti afterburn valve thing (The book kind of said that's what it is). I kind of thought that was the problem before, but it appears the hose that runs across the top of the firewall was partially missing, and the canister thing it feeds looked like it hooked to nothing. LOL. Anyway, that's all taken care of, most excellent. Back to donuts on mountain tops with 2 feet of snow baby! (while being able to see).