Help! 82 - AC/Heater control trouble shooting

[73-81 BST]

FINAL winter project before SMOKE hits the road again.

My AC/heater control will not switch out of defrost mode.....blower switch works so does the temp. Is this a AC/heater control issue or a relay?

Thanks

 

[bill81vette]

It sounds like you have a vacuum problem...
check in behind the glove box to see if some of mickey's relatives decided to chew thru your vacuum lines,and didn't make any nests back there.
Good Luck!!!!!

 

[Yoda]

Is the problem with the lever switch not moving over to the air-conditioning and seems hungup about in the middle of the arc??

I had issue's with mine getting hung up, then I forced it trying to get it to work and then it felt like nothing was attached to it.. I ended up taking it out of the console. We were leaving the next day for an event, so I got out the GM Shop manual and made a "Bubba Fix" that has lasted more than 10 years

As I recall I made a small plastic (Teflon) washer to hold the cam in place when the lever moved from one side of the switch to the other to turn on the air-conditioning:

It was a pita to get to and get out. I removed both side panels on the console, and skinned my hands up real good too :bash

If the switch seems to be working and just not turning on the air, you may still need to check the diaphram and vacuum lines, as Bill points out

Good Luck, air in our old C3's isn't the best to begin with, BUT NO Air-Conditioning is :nono because it's better than none :dance

Bud

 

[73-81 BST]

Thanks...all the switches move....the unit has a nice hissing noise...Looks like Ac this year will be 4 x 70....tops off / windows down 70mph cruise...

I have added this repair to my 2010 Winter project list

 

[Phill]

i had a similar problem on my 79. it turned out to be a loose vacuum line going to the back of the switch.

 

[jdp6000]

Thanks...all the switches move....the unit has a nice hissing noise...Looks like Ac this year will be 4 x 70....tops off / windows down 70mph cruise...

I have added this repair to my 2010 Winter project list

It shouldn't have a nice hiss. Remove the passengerside side panel and see if the vaccum line slipped off. Could be a real simple fix.

Jim