C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

1977 Electrical Problem

Thread Tools
 
Search this Thread
 
Old Jan 14, 2012 | 07:41 PM
  #1  
Pelayo114's Avatar
Pelayo114
Thread Starter
Instructor
 
Joined: Jan 2011
Posts: 221
Likes: 1
From: Sylmar CA
Default 1977 Electrical Problem

I just replaced all the fuses and bulbs on my car. Everything was working fine with the key open and the car off. I start the car up and as soon as I do my turn signals don't work anymore and when I step on the brakes, the left rear light won't turn on. Anyone have any ideas why?



Also this 'GEN' light keeps flickering on and off in my car, anyone know what it is, what it means, if its supposed to be on or off and how I can fix this?

Reply
Old Jan 15, 2012 | 08:59 AM
  #2  
jdp6000's Avatar
jdp6000
Melting Slicks
10 Year Member
 
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
Default

Did you have a problem before you changed the fuses? You may have activated a circuit with the new fuse that was a pre-existing problem.

You may have installed the wrong bulb somewhere. Start by pulling the one that does not work, left rear.

I see in the pic of your guage the volts are well below 13, that could also cause the GEN light to flicker. When you give it gas do the Volts climb....they should.

Jim
Reply
Old Jan 15, 2012 | 10:16 AM
  #3  
captl27's Avatar
captl27
Instructor
10 Year Member
 
Joined: Jan 2006
Posts: 228
Likes: 1
From: Warwick New York
Default

I would check the grounds both in the back by the lights themselves and in the front near the alternator. It seems that the lights are useing a source to ground that is taken away when you start the car. Sound like you have your work cut out for you. good luck
Reply
Old Jan 15, 2012 | 02:02 PM
  #4  
Pelayo114's Avatar
Pelayo114
Thread Starter
Instructor
 
Joined: Jan 2011
Posts: 221
Likes: 1
From: Sylmar CA
Default

Jim, yeah the problem existed before I changed the fuses, that's why I changed them to see if it would fix the problem.
Also the bulbs all work because when the car is off but the key is turned, all the lights work sometimes, and sometimes the left rear stop light won't work. Although the tail light works. It works sometimes and sometimes it doesn't. Same goes for the turn signals. And I don't know why this is happening.

And in the picture its with the car off at 12 volts. With the car on its at around like 15 volts approximately.

captl27, how do I check the ground in the back lights? Is it coming straight from the bulb or how?
Reply
Old Jan 16, 2012 | 09:21 AM
  #5  
captl27's Avatar
captl27
Instructor
10 Year Member
 
Joined: Jan 2006
Posts: 228
Likes: 1
From: Warwick New York
Default

The grounds are throughout the car. you should see screws with wires bolted to the metal parts in the rear bumper section of the car. A test light with and extra long lead clamped to the the positive pole of the battery can help test these problems. If you have your test light hooked to the positive terminal and you touch it to the metal part of the light socket it should light no mater where the ignition switch is.

Last edited by captl27; Jan 16, 2012 at 09:23 AM.
Reply
Old Jan 16, 2012 | 11:41 AM
  #6  
jdp6000's Avatar
jdp6000
Melting Slicks
10 Year Member
 
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
Default

Originally Posted by Pelayo114
Jim, yeah the problem existed before I changed the fuses, that's why I changed them to see if it would fix the problem.
Also the bulbs all work because when the car is off but the key is turned, all the lights work sometimes, and sometimes the left rear stop light won't work. Although the tail light works. It works sometimes and sometimes it doesn't. Same goes for the turn signals. And I don't know why this is happening.

And in the picture its with the car off at 12 volts. With the car on its at around like 15 volts approximately.

captl27, how do I check the ground in the back lights? Is it coming straight from the bulb or how?
You need to isolate the problem. Start by pulling fuses. It could be your signal switch.

I am not familiar with 77 fuse system. First turn everything off like the radio.

Pull a fuse and start the car. See if the gen light stops flickering. If the pulled fuse dosen't do it put it back in and pull another and keep repeating the proces until you find the one that eliminates the gen flash.

As each fuse is pulled go out and eyebal the lights and see if there is a change in how bright they are.

Its process of elimination.
Reply
Old Jan 21, 2012 | 02:58 PM
  #7  
Pelayo114's Avatar
Pelayo114
Thread Starter
Instructor
 
Joined: Jan 2011
Posts: 221
Likes: 1
From: Sylmar CA
Default

The fuses seem to temporarily fix the problem. I pull them and put in the ones for the stop and taillights. Pop them back in(still working) and the lights all work, except interior dash lights. And then while driving they die again. I have been meaning to check it out but its been raining here so I haven't had a chance to check the electrical outside.
Another thing the step lights and the light by the t tops came on and stay on, no matter what. It happened when I was trying to pull the circuit breaker to replace it in the fuse box. Battery was still hooked up. Then I smelled some smoke coming from under the hood near the fuse box area. Since then the lights have stayed on and I don't know why. I popped out the fuse to keep my battery from dying and keep the lights off. Any ideas?
And I figured out the 'GEN' light problem. Some wires were loose on my alternator. I rewired it and hooked it up and the light is off now
I'll check the grounds when its not raining outside anymore lol
Reply
Old Jan 22, 2012 | 08:13 AM
  #8  
jdp6000's Avatar
jdp6000
Melting Slicks
10 Year Member
 
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
Default

Originally Posted by Pelayo114
The fuses seem to temporarily fix the problem. I pull them and put in the ones for the stop and taillights. Pop them back in(still working) and the lights all work, except interior dash lights. And then while driving they die again. I have been meaning to check it out but its been raining here so I haven't had a chance to check the electrical outside.
Another thing the step lights and the light by the t tops came on and stay on, no matter what. It happened when I was trying to pull the circuit breaker to replace it in the fuse box. Battery was still hooked up. Then I smelled some smoke coming from under the hood near the fuse box area. Since then the lights have stayed on and I don't know why. I popped out the fuse to keep my battery from dying and keep the lights off. Any ideas?
And I figured out the 'GEN' light problem. Some wires were loose on my alternator. I rewired it and hooked it up and the light is off now
I'll check the grounds when its not raining outside anymore lol
It sounds like the problem is in the main connection behind the fuse panel especially if you smelled smoke and the lights now stay on. I suspect you have some wires melted together back there.

I would disconnect the battery and remove the fuse block. Unfortunately I dont' know how to do this on a 77. There will be a big plug back there. You need to get at it.

Jim
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

5 Best & 5 Most Overrated Corvette Track Packages of All Time!

 Joe Kucinski
story-1

Every 2027 Corvette Engine Explained

 Joe Kucinski
story-2

Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

 Verdad Gallardo
story-3

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-4

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-5

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-6

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-7

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-8

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-9

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
Old Jan 22, 2012 | 08:45 AM
  #9  
Flemgunner's Avatar
Flemgunner
Advanced
 
Joined: Apr 2009
Posts: 81
Likes: 0
From: Scott La
Default

To remove the fuse block there is a rivet and a screw in the interior and a bolt on the plugs on the firewall under the hood. After you remove those just pull it apart
Reply
Old Jan 22, 2012 | 10:50 AM
  #10  
Pelayo114's Avatar
Pelayo114
Thread Starter
Instructor
 
Joined: Jan 2011
Posts: 221
Likes: 1
From: Sylmar CA
Default

Oh yeah I've taken that apart before. Could that be the problem?i will take it apart today and take a look at it.
Reply
Old Aug 8, 2014 | 08:29 PM
  #11  
Nodeman's Avatar
Nodeman
1st Gear
 
Joined: Mar 2010
Posts: 1
Likes: 0
From: Ocala Fla.
Default

I have a similar problem when I turn on the lights the headlights come on but the tail lights do not. The brake lights work fine, no gauge lights also, any thoughts?
Reply

Get notified of new replies

To 1977 Electrical Problem





All times are GMT -4. The time now is 07:34 AM.

story-0
5 Best & 5 Most Overrated Corvette Track Packages of All Time!

Slideshow: The 5 best and 5 most overrated Corvette track packages ever.

By Joe Kucinski | 2026-06-09 12:46:45


VIEW MORE
story-1
Every 2027 Corvette Engine Explained

Slideshow: Every 2027 Corvette engine explained

By Joe Kucinski | 2026-06-09 12:16:31


VIEW MORE
story-2
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.

By Verdad Gallardo | 2026-06-08 19:53:43


VIEW MORE
story-3
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-4
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-5
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-6
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-7
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-8
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-9
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE