Wiring Issues - close to shooting myself
Thread Starter
Instructor
Joined: Apr 2017
Posts: 205
Likes: 4
Wiring Issues - close to shooting myself
1975 - coupe
Replaced all bulbs with new.... chasing down some issues and I'm about at my wits end.
WORKING: illumination bulbs, blinkers, back up lights, hazard lights, lights on warning (if you turn off ign and leave lights on), courtesy lights.
PRESUMED WORKING: headlights, high beams (and indicator).
NOT WORKING:
Car isn't ready to be started yet - in the middle of a lot of projects, but lights and high beams WERE working before I tore into it.
That said, so was the parking brake warning and door ajar warnings - they "were" working.
Checked all fuses - all good.
Traced the blue wire from the door ajar switches all the way to the bulb and that's good. Both door ajar switches are good. I don't know where to trace the white wire to - so I'm presuming the issue is related.
As to the parking brake warning - that's really odd.
As to the FSB light - IDK if it was that way prior as there was no bulb in the socket... maybe that's a clue from some PO... instead of fixing, just pull the bulb -
Any insights would be appreciated... I just don't know where to go from here.
Thanks,
Len
Replaced all bulbs with new.... chasing down some issues and I'm about at my wits end.
WORKING: illumination bulbs, blinkers, back up lights, hazard lights, lights on warning (if you turn off ign and leave lights on), courtesy lights.
PRESUMED WORKING: headlights, high beams (and indicator).
NOT WORKING:
- Parking brake warning
- Door ajar warning
- Fasten Seat Belts (constantly lit when ign in run position)
Car isn't ready to be started yet - in the middle of a lot of projects, but lights and high beams WERE working before I tore into it.
That said, so was the parking brake warning and door ajar warnings - they "were" working.
Checked all fuses - all good.
Traced the blue wire from the door ajar switches all the way to the bulb and that's good. Both door ajar switches are good. I don't know where to trace the white wire to - so I'm presuming the issue is related.
As to the parking brake warning - that's really odd.
As to the FSB light - IDK if it was that way prior as there was no bulb in the socket... maybe that's a clue from some PO... instead of fixing, just pull the bulb -
Any insights would be appreciated... I just don't know where to go from here.
Thanks,
Len
Melting Slicks
Joined: Oct 2008
Posts: 2,154
Likes: 69
From: Regina Sk Canada
These cars are very GROUND dependant. When you move a wire that has been in a single position for the last 40 years, they tend not to like that.. You may have a broken wire at a switch, or a poor ground.
Race Director
Joined: Mar 2016
Posts: 14,428
Likes: 8,232
From: Napa Valley California
You may need to trace each individual wire with an ohm meter, check continuity and check the physical condition of each wire as well. Wires can get pinched or crushed when someone is up under the dash or pulling and replacing parts or components. If you don't have one, purchase a wiring diagram and AIM for your model and year. Keep in mind that a wiring malfunction or modification "anywhere" in the system could effect a complete separate circuit. Have patients, pay attention to wiring color schemes, inspect each connection and connector, then see how much hair you have pulled out in the process. Good luck.
Instructor
Joined: Sep 2015
Posts: 122
Likes: 17
From: MA
electrical nirvana
Len,
Don't give up! It took me about a year to finally reach electrical nirvana. I used the AIM, a shop manual and a wiring diagram. I got my diagram from a forum member who, I think has other years. You just have to send him an email: His name is, Emerson Gallup and his email is
papawana@verizon.net.
Good Luck,
Michael
Don't give up! It took me about a year to finally reach electrical nirvana. I used the AIM, a shop manual and a wiring diagram. I got my diagram from a forum member who, I think has other years. You just have to send him an email: His name is, Emerson Gallup and his email is
papawana@verizon.net.
Good Luck,
Michael
Thread Starter
Instructor
Joined: Apr 2017
Posts: 205
Likes: 4
Well, turns out that I "jiggled" a connection under the left kick panel (near the fuse box) and the brake warning, headlight warning, and door ajar all started working again.
As to the fasten seat belt being constantly on, that's been an ongoing issue.
I read somewhere that the 75 wiring changed between earlier cars and later cars. I think my 75 falls in the middle somewhere of the production year... so onward through the fog.
Thanks for the tips!
As to the fasten seat belt being constantly on, that's been an ongoing issue.
I read somewhere that the 75 wiring changed between earlier cars and later cars. I think my 75 falls in the middle somewhere of the production year... so onward through the fog.
Thanks for the tips!
Burning Brakes
Joined: Oct 2013
Posts: 1,116
Likes: 520
From: McClellandtown, Pa.
Well, turns out that I "jiggled" a connection under the left kick panel (near the fuse box) and the brake warning, headlight warning, and door ajar all started working again.
As to the fasten seat belt being constantly on, that's been an ongoing issue.
I read somewhere that the 75 wiring changed between earlier cars and later cars. I think my 75 falls in the middle somewhere of the production year... so onward through the fog.
Thanks for the tips!
As to the fasten seat belt being constantly on, that's been an ongoing issue.
I read somewhere that the 75 wiring changed between earlier cars and later cars. I think my 75 falls in the middle somewhere of the production year... so onward through the fog.
Thanks for the tips!
Just going out on a limb here! I'm not sure about the 75, but do your seats still have the weight sensitive switch attached to the springs under the seat bottoms? So that when weight is applied to the seat the switch either opens or closes( can't remember which) thus causing the light and buzzer to come on. Here is a picture of it from my passenger seat on my 73. It was only on the passenger seat in 73. Any way my light kept staying on until I checked out this switch. It has to be arched alittle (bowed) so the contact stays open. Then when weight is applied it levels out to turn on the light. You can see the little wire contact in the second photo. That's what you need to adjust to make things work as they should. Trial and error!
Just a suggestion,
Jimmy
PS: This may be moot, if you don't have your original seat belts connected. This switch plugs into the right side belt retractor on the 73-74's.
Last edited by Tooch1; Jul 26, 2017 at 06:09 PM. Reason: Added info.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Thread Starter
Instructor
Joined: Apr 2017
Posts: 205
Likes: 4
I hooked up a relay to the FSB light so that when the driver belt is connected the light will go out.
As to why it was always "ON" - will remain a mystery for some other owner down the road.
I have the functionality that I want for now.
Regarding the switches under the seats - there are NO switches under either seat, and there isn't any indication that they were ever there... IE no signs of them being removed.
As to why it was always "ON" - will remain a mystery for some other owner down the road.
I have the functionality that I want for now.
Regarding the switches under the seats - there are NO switches under either seat, and there isn't any indication that they were ever there... IE no signs of them being removed.