Topic: 1979 Smoke from A/C Control Switch
in Forum: C3 Electrical
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I keep getting smoke from my A/C rotary switch after I turn the A/C off. I have cleaned the contacts twice in the car without pulling the switch out of the car. This seems to work for a while. Should I replace the panel or is there something else I can do?
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
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#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Place a plastic bag over it, and catch the smoke, so you can put it back in. Once the switch runs out of smoke, it will no longer work.
Sorry....I couldn't help meself!
If you have a switch, or other electrical component that is smoking, you really should replace it, and try to determine if it failed just due to old age, or if there is something else going on that is causing it to overheat, or short out. Turning the A/C OFF should eliminate any power going thu the switch, but apparently, yours still has something weird going on. That's kinda scary....
Do you also smell something burning...like plastic?
It's possible that your vacuum switch is acting goofy, and you're getting fuel vapors thru the line....not really something that happens a lot, but I have seen it once or twice over the years...
Adams' Apple 2011-04-11 10:18:37
Sorry....I couldn't help meself!
If you have a switch, or other electrical component that is smoking, you really should replace it, and try to determine if it failed just due to old age, or if there is something else going on that is causing it to overheat, or short out. Turning the A/C OFF should eliminate any power going thu the switch, but apparently, yours still has something weird going on. That's kinda scary....
Do you also smell something burning...like plastic?
It's possible that your vacuum switch is acting goofy, and you're getting fuel vapors thru the line....not really something that happens a lot, but I have seen it once or twice over the years...
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
How much smoke are we talking about here? Just a little poof, or a steady stream?
What are you using to "clean" the contacts? If your putting WD40 on them, that could be the problem. The oil in it may be causing the smoke when the contacts spark when you turn it off. If that's all it is, then I wouldn't really worry about it. Instead of using a spray on them, you could use a FINE file to clean the contacts, or even a fine grit of sandpaper/emery cloth.
What are you using to "clean" the contacts? If your putting WD40 on them, that could be the problem. The oil in it may be causing the smoke when the contacts spark when you turn it off. If that's all it is, then I wouldn't really worry about it. Instead of using a spray on them, you could use a FINE file to clean the contacts, or even a fine grit of sandpaper/emery cloth.
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Steady stream, using CRC QD Electronic Cleaner, but remember I am trying to do it w/o removing the assy. I don't want to, but short of replacing it, it sounds like I need to remove it to get a good look at it.
in Forum: C3 Electrical
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