My '77 heater/AC control lever is stuck in "heat" position (top slide). The bottom slide (temp control works OK). The top one will not move. I removed the side console panels and I can't see any obstructions. Is there another place to look?? Or, do I need to replace the assemble ($140) and solve my problem. Seems like there should be a valve to shutoff the hot H2O from the heater coil and maybe thats my problem.

Thanks for any advice/suggestions you can give.

Terry

 

Be careful, my 81 got stuck last year and I forced it to move. Since then I have a hissing sound that comes from that area under the console. I thought that maybe I jerked a vacuum line loose or something.

I think after I eat lunch I will go down and take a look at what I did a year ago. Lol I am slow like that. I had been without my horn since I bought my new steering wheel almost two years ago. I fixed that a couple of nights ago.

 

You are talking about the lever that is closest to the radio, right? On the underside of the control assembly you will see the vacuum lines going to the control. They are attached to teh vacuum switch that you can still buy from GM. There are two phillips head screws that secure the vacuum switch to the lever that is binding. Remove the two screws and allow the vacuum switch to be removed. You may to carefully remove the internal tooth retainers that secure the vacuum hose connector to teh switch first so that you can gain access to the inner phillips screw. Check to see if your lever moves now. If it does not, Then it gets a bit more involved in removing the control from the underside of the console. I remove them quite often when replacing the lens and face to make them look new but it is a bit tight working area. Usually if the vacuum switch retaining rivet breaks due to being plastic and causes it to lock up. Or.... it is the divider palte that separates the two levers of the control and something has shifted or broke causing the lever to catch this divider. If you get it out you will see that it is really a simple control to inspect and find the problem. If you find that you can not release the cable from it, be careful because it will still be able to be removed with the cable attached but by now the part of the cable that is secured to the control is aged and brittle so treat it carefully without alot of twisting and undue pressure. If you have any questions I can walk you through it over the phone if you call me at work.

 

Many thanks for you help. I'll do some work on it today and see what I can find....

Terry

 

Here is an exploded view of the control. About the only thing I can think of that would lock up the upper lever is exactly what grandmaster said. The vacuum select switch.

When the control is out of the car it is easy to rebuild too!


18243

 

Was it stuck when you bought it?
Mine was.
Bubba had zip tied the flap at the end of the cable to keep the hot air from coming out the heater core.
I had replaced most of the heater controls before I found the darn little zip tie in place.
Mine is also a 77

 

No, it was working fine during the winter when I needed heater but I drove the other day and wanted some A/C and it was "locked" in the heat mode.

Willcox, thanks for the diagram. Now I know what I'm supposed to look for

Terry