Dash light do not work
Thread Starter
Instructor
Joined: Nov 2013
Posts: 166
Likes: 8
From: Acworth GA
Dash light do not work
My dash lights do not come on when I turn on the headlights. I have rotated the headlight switch in both direction fully.
I need an electrical diagram for a 1978 Vette dash. I looked in my manuals but nada. I looked online but I could not find one.
Can anyone send me one or point me to one.
Thanks
Rich
I need an electrical diagram for a 1978 Vette dash. I looked in my manuals but nada. I looked online but I could not find one.
Can anyone send me one or point me to one.
Thanks
Rich
Burning Brakes
Joined: May 2014
Posts: 1,094
Likes: 16
From: Los Angeles California
Thread Starter
Instructor
Joined: Nov 2013
Posts: 166
Likes: 8
From: Acworth GA
Burning Brakes
Joined: May 2014
Posts: 1,094
Likes: 16
From: Los Angeles California
he will. he has been doing it for years great guy. I got mine from him in april. I just don't think mine will work for you as these cars vary from year to year very minor but some things are different
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,847
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
go to the instrument lamps fuse.. with a volt meter.. With the lamp pulled in the on position, test for power on the left side of the fuse. If you have power there then the issue is past the fuse so test the fuse... If the fuse is good, and you don't have power there then more thank likely the issue is the headlamp switch.
The power to this fuse leaves the headlamp switch on the green wire. It goes to the fuse panel and then comes out gray. (to the lamps).
Imho,
Willcox
The power to this fuse leaves the headlamp switch on the green wire. It goes to the fuse panel and then comes out gray. (to the lamps).
Imho,
Willcox
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
My dash lights do not come on when I turn on the headlights. I have rotated the headlight switch in both direction fully.
I need an electrical diagram for a 1978 Vette dash. I looked in my manuals but nada. I looked online but I could not find one.
Can anyone send me one or point me to one.
Thanks
Rich
I need an electrical diagram for a 1978 Vette dash. I looked in my manuals but nada. I looked online but I could not find one.
Can anyone send me one or point me to one.
Thanks
Rich
Did they ever come on? Or was it just an abrupt "Hey! What happened to the instrument lights?" thing?
I like Willcox's approach to the problem.
Steve
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,847
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
I cheated... lol. I just helped the shop on Friday with the same diagnosis. No power at the left side of the fuse. We replaced the headlamp switch and the problem was solved.
If he has power on and after the fuse, then I would go to the pcb connector behind the speedo and tach. It's common for the fingers on the printed circuit board to come loose and one may not be touching or shorted out. There are instructions here on our site for removing the dash cluster. (also the easiest way to remove/replace the headlamp switch on a 78-82.
Corvette Speedometer and Tach Housing Removal Instructions 1978-1982
If he has power on and after the fuse, then I would go to the pcb connector behind the speedo and tach. It's common for the fingers on the printed circuit board to come loose and one may not be touching or shorted out. There are instructions here on our site for removing the dash cluster. (also the easiest way to remove/replace the headlamp switch on a 78-82.
Corvette Speedometer and Tach Housing Removal Instructions 1978-1982
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Team Owner
Joined: May 2005
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The instrument dimmer is part of the headlight switch. If it's not a fuse, then it's the switch that needs replacing.
The other option is to hardwire the instrument lights without the dimmer, but then you will have full blast instrument brightness all the time.
The other option is to hardwire the instrument lights without the dimmer, but then you will have full blast instrument brightness all the time.
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
The instrument dimmer is part of the headlight switch. If it's not a fuse, then it's the switch that needs replacing.
I replaced mine because of the flakey dimmer function, AND the burnt looking ceramic rheostat.
The other option is to hardwire the instrument lights without the dimmer, but then you will have full blast instrument brightness all the time.
Not a viable option, for me anyway.
I replaced mine because of the flakey dimmer function, AND the burnt looking ceramic rheostat.
The other option is to hardwire the instrument lights without the dimmer, but then you will have full blast instrument brightness all the time.
Not a viable option, for me anyway.
Steve
Thread Starter
Instructor
Joined: Nov 2013
Posts: 166
Likes: 8
From: Acworth GA
Thanks for the responses. I did not get a notice in my email that anyone had responded past the first couple. I was working on other things and had not gotten back to the dash light thing yet but when I do I'll make sure I post a the results.
Thread Starter
Instructor
Joined: Nov 2013
Posts: 166
Likes: 8
From: Acworth GA
I cheated... lol. I just helped the shop on Friday with the same diagnosis. No power at the left side of the fuse. We replaced the headlamp switch and the problem was solved.
If he has power on and after the fuse, then I would go to the pcb connector behind the speedo and tach. It's common for the fingers on the printed circuit board to come loose and one may not be touching or shorted out. There are instructions here on our site for removing the dash cluster. (also the easiest way to remove/replace the headlamp switch on a 78-82.
Corvette Speedometer and Tach Housing Removal Instructions 1978-1982
If he has power on and after the fuse, then I would go to the pcb connector behind the speedo and tach. It's common for the fingers on the printed circuit board to come loose and one may not be touching or shorted out. There are instructions here on our site for removing the dash cluster. (also the easiest way to remove/replace the headlamp switch on a 78-82.
Corvette Speedometer and Tach Housing Removal Instructions 1978-1982
Thanks for the link, that was probably going to be my next question...."how do I get the dash out"...was not looking forward to that.
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
I don't recommend wrapping a fuse in tin foil, insert it in the fuse box, and then look for the place where the origin of the fire started.
Steve
Thread Starter
Instructor
Joined: Nov 2013
Posts: 166
Likes: 8
From: Acworth GA
I finally got to look at the dash lights problem again. Under the dash on the drivers side next to the fender is a fuse block. In that block is a fuse labeled "gauges", it's right above the "radio" fuse. I assumed that this is for the "gauge" lights. I spent all my time reading 12v on it when I turned on the ignition key etc, etc, etc, I wasted my time.
I finally looked at the bottom of the block an saw one called "inst lps", in printing so dim I had not noticed it before. It was blown......they work now.
By the way, I did not have a fuse that was physically that small and I did not want to go to the auto parts store and buy a little fuse. I noticed that the plug-in fuses I had with spade connectors have the same pitch (width) as the little fuse. So I bent the prongs back to be flush with the body of the little guy and stuck it in there...wala, I have dash lights.
Thank you for all the advice and help, I learned a bunch about my Vette.
I finally looked at the bottom of the block an saw one called "inst lps", in printing so dim I had not noticed it before. It was blown......they work now.
By the way, I did not have a fuse that was physically that small and I did not want to go to the auto parts store and buy a little fuse. I noticed that the plug-in fuses I had with spade connectors have the same pitch (width) as the little fuse. So I bent the prongs back to be flush with the body of the little guy and stuck it in there...wala, I have dash lights.
Thank you for all the advice and help, I learned a bunch about my Vette.
Last edited by Rich123; Sep 21, 2014 at 07:37 PM.
Burning Brakes
Joined: Oct 2013
Posts: 992
Likes: 28
From: Sutton MA
Rich123 thanks for the follow up, it lead me to investigate our fuse panel a little closer, I found ours to be top left on the block, and it did NOT have a fuse. Put one in and lights all work 
This forum rocks.
This forum rocks.
Thread Starter
Instructor
Joined: Nov 2013
Posts: 166
Likes: 8
From: Acworth GA
Isn't it nice to be able to drive at night without a flashlight to see the gauges and a GPS to see how fast you're going.