Sponsored Content
s
Former Member
Send PMLeavenworth, KS - USA
Joined: 1/24/2007
Posts: 426
Vette(s): MM Red 1971 T-top,LS5,4-speed, black leather C5 seats, Hooker sidepipes.
Previous: 64 Coupe, 65 Roadster L76 / N14
This is a quickie for a friend with an '80 model.
He's about to be taken to the cleaners (AGAIN!) by the local garage.
His mechanic tells him that his HEADLIGHT SWITCH is bad.
Symptoms were (1) headlights won't raise, (2) rear window defroster won't operate, and (3) heater won't operate.
Does this HEADLIGHT SWITCH control all of these functions? Raising the headlights? Thought that was all vacuum?
What does this sound like to the experts out there?
Appreciate a quick response to avoid another rip-off. Thanx! Mike
Be the first to like this post
Sign In to Like this post
Sign In to Like this post
SPONSOR AD:: (Our Sponsors help support Vette Registry)
Lifetime Member
Send PMSHELBYVILLE, TN - USA
Joined: 7/5/2002
Posts: 3944
Vette(s): 1976 L48 auto
1978 L82 4speed
1994 LT1 6speed
1978 L82 4speed
1994 LT1 6speed
no doubt a Joel question to answer, since he's got the wiring diagrams, but.. logically thinking(dangerous i know, considering all the great engineers that GM hires), the rear window defrost should be on a circuit to itself.. and as for the heater, do you mean the fan won't come on??.. if so, then, it too is on a seperate circuit. The raising of the headlights are operated by vacuum... there is a valve on the headlight switch that provides the vaccuum to the actuators once the pull switch is pulled all the way back... it is possible that the valve is shot, or that the vaccuum hoses are just dry rotted and leaky.... however if it is the hoses, then its not the switch... kinda sounds to me like 'things' are not as they seem where-ever this vette is being cared for.... but then again i'm not known for my worldly intuition.... :)
StingrayJim 
NCM Lifetime Member #1936
Stingray's '76���������������������������� StingrayJr's '78���������������������������Lil Red '94 
(click each one to see a bigger version)
Be the first to like this post
Sign In to Like this post
Sign In to Like this post
Lifetime Member
Moderator
Send PMModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22720
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
A bad headlight switch can keep the lights from raising, but only due to a vacuum issue with the switch, not electrical. If the headlights actually light up, then the electrical part of the switch is working. The switch can dry out, and cause the lights to not raise, as the headlight vacuum signal does go thru the headlight switch.
The headlight switch ain't got dick to do with the rear defog, or the blower motor. Those things have different problems, possibly as simple as a fuse...
I can e-mail you some vac. troubleshooting info...I shall do that now.
I would tell yer buddy to get his car out of there...
Mike..."You've Got Mail!!"
(MS Word Doc)Adams' Apple 2008-09-03 19:07:59
The headlight switch ain't got dick to do with the rear defog, or the blower motor. Those things have different problems, possibly as simple as a fuse...
I can e-mail you some vac. troubleshooting info...I shall do that now.
I would tell yer buddy to get his car out of there...
Mike..."You've Got Mail!!"
(MS Word Doc)
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"
Be the first to like this post
Sign In to Like this post
Sign In to Like this post
s
Former Member
Send PMLeavenworth, KS - USA
Joined: 1/24/2007
Posts: 426
Vette(s): MM Red 1971 T-top,LS5,4-speed, black leather C5 seats, Hooker sidepipes.
Previous: 64 Coupe, 65 Roadster L76 / N14
Thanks all. You did not dissapoint! And I especially appreciate the Vacuum Troubleshooting Guide that Joel sent! 
Your thoughts echoed mine. This poor soul is an "owner" of a 1980 since he bought it new, but can't even change the oil. As a result, he has been taken to the cleaners a number of times by his "mechanic of choice." I was pretty sure this was another re-run.
Thanks for weighing in and the help. I strongly recommended a change in mechanics. I also provided the owner with a copy of Joel's Guide for the mechanic who can obviously use it. Whether or not he will is another question. . . .
What a great forum this is! 
Be the first to like this post
Sign In to Like this post
Sign In to Like this post
in Forum: C3 Electrical, Body and Interior
Sponsored Content