Switch next to the AC fan speed switch function?
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Heel & Toe
Joined: Mar 2023
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Switch next to the AC fan speed switch function?
So I just bought a 79 vette 5 days ago and I’m new to it and messed with just about every button and switch on it but can’t find out what the switch does on the left of the AC fan speed switch it stays in the middle and can go up and down but automatically goes back to the middle and makes a slight tick sound near the e-break
if anyone knows what it does please let me know
-thank you
if anyone knows what it does please let me know
-thank you
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Heel & Toe
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Yes
Racer
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From: Midwest
A 1979 Corvette Owners Manual answers all such fundamental questions and it ony has a few errors in it. Below is some info not found in the manual that some may find interesting.
As previousy mentioned, it is your rear window defogger switch. RWD was actually an extra cost option in 1979 that never did become standard C3 equipment even though it was both safety related and quite popular.
Your rear window glass should have wire filiments running its length as the C3 RWD system was changed from a forced air type to an electrical unit starting in 1976.
The switch lever became self-centering in 1978 to work with the new idea of having a timer automatically turn the unit off after a period of time. That auto shut-off feature was important since the RWD places a considerable draw on the alternator, especially with the large rear window of the 1978-1982 C3. Some owners would activate the RWD and then forget it, not really concerned with the green light. It might run for hours when it was only needed for perhaps 10 minutes?!
GM found a solution that didn't require anything from the owner. 
As previousy mentioned, it is your rear window defogger switch. RWD was actually an extra cost option in 1979 that never did become standard C3 equipment even though it was both safety related and quite popular.
Your rear window glass should have wire filiments running its length as the C3 RWD system was changed from a forced air type to an electrical unit starting in 1976.
The switch lever became self-centering in 1978 to work with the new idea of having a timer automatically turn the unit off after a period of time. That auto shut-off feature was important since the RWD places a considerable draw on the alternator, especially with the large rear window of the 1978-1982 C3. Some owners would activate the RWD and then forget it, not really concerned with the green light. It might run for hours when it was only needed for perhaps 10 minutes?!
GM found a solution that didn't require anything from the owner. Corvette Stories
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