Electrical problems
Thread Starter
Heel & Toe
Joined: Feb 2020
Posts: 18
Likes: 6
From: St. Marys Georgia
Electrical problems
I have a 1975 coupe. The chassis has been rebuilt and I am preparing to replace the interior. I upgraded the High and Low beam lights to be powered directly from the battery, via 2 Relays (works well). I replaced the Pneumatic headlight doors with Mazda headlight door mechanism, powered through relays initialized by the dimmer switch being powered by the light switch (works well). I also added a late model GM vacuum pump to operate the brake booster (works well). Replaced the GM A/C with Vintage air system and added a Condenser assist fan which works with high engine temp or High head pressure from the A/C.
Now the problem: none of the following will power up: 1 directional signal lamps; 2. Marker lamps 3. Taillights or brake lights; 4. No power to the bottom 3 fuses in the bulkhead connector block? I am baffled, please help.
Now the problem: none of the following will power up: 1 directional signal lamps; 2. Marker lamps 3. Taillights or brake lights; 4. No power to the bottom 3 fuses in the bulkhead connector block? I am baffled, please help.
Race Director
Joined: Oct 2019
Posts: 10,735
Likes: 63
From: Deep in the Pisgah National Forest
Check the fusible links. On my 81 there were two; one powered the always on circuits, and the other powered the fuse panel. The single 16ga link for always on also powered the ignition circuit. They can burn and still stay together.
I replaced my fuse links with a small fuse panel containing 3x40 amp bolt-on fuses. The panel is on the bulkhead where I can see it and powered that through a #4 battery cable in a conduit. This also gave me a junction to power two self-resetting circuit breakers that power my headlight relays.
I replaced my fuse links with a small fuse panel containing 3x40 amp bolt-on fuses. The panel is on the bulkhead where I can see it and powered that through a #4 battery cable in a conduit. This also gave me a junction to power two self-resetting circuit breakers that power my headlight relays.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,113
Likes: 9,241
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
check your wiring diagram. On my 68 the power goes to the headlight switch then down to the fuse panel for those then back up and out to the receptacles...its weird. So try again with the headlight switch pulled out. If you still dont have power pull the fuse block and look at the back and see if the wiring is good. Mine was fried and had to be resoldered
Thread Starter
Heel & Toe
Joined: Feb 2020
Posts: 18
Likes: 6
From: St. Marys Georgia
When I really got my face into it under the steering column I noticed there was a lot of corrosion. Probably from the leaking T-Tops, while it sat outside 2 years, uncovered.
I ordered a 21 circuit wiring harness on Amazon and a 6 receptacle Relay box, just to clean up the 5 relays I installed. I'm just going to pull new wires, do some soldering and wrapping, and clean this mess up.
Have you heard of anyone moving the fuse box out from under the steering area to another easier to get to location? I'm going to do it, just hate to re-invent the wheel.
And I really appreciate you taking the time and giving me your ideas on this issue.
Mike
I ordered a 21 circuit wiring harness on Amazon and a 6 receptacle Relay box, just to clean up the 5 relays I installed. I'm just going to pull new wires, do some soldering and wrapping, and clean this mess up.
Have you heard of anyone moving the fuse box out from under the steering area to another easier to get to location? I'm going to do it, just hate to re-invent the wheel.
And I really appreciate you taking the time and giving me your ideas on this issue.
Mike
Thread Starter
Heel & Toe
Joined: Feb 2020
Posts: 18
Likes: 6
From: St. Marys Georgia
I followed the diagram and the wiring does look confusing. As I told Yadkin, I'm just going to replace the corroded fuse panel and rewire the whole car. I made so many changes in how it works, it will be an aggravating job, but it will be neater in the long run.
I also would like to move the fuse panel out of the wormhole it's in, so I can get to it with the seats in the car. Do you have any suggestions or know anyone who has done it? I'm 72, 80% Viet Nam disabled, and busted it up from a motorcycle wreck 19 years ago.
Thanks for your Suggestion Rescue Rogers.
I also would like to move the fuse panel out of the wormhole it's in, so I can get to it with the seats in the car. Do you have any suggestions or know anyone who has done it? I'm 72, 80% Viet Nam disabled, and busted it up from a motorcycle wreck 19 years ago.
Thanks for your Suggestion Rescue Rogers.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,113
Likes: 9,241
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Anything is possible its just finding a suitable location.....There is a lot of room behind the passegers side dash but you would have to pull the dash to access it. You could buy an aftermarket center console that has a storage compartment and put it in there. It. is a bear to get under the dash for sure. If you havent had it apart, the fuse panel is attached to the cabin wiring harness that then meets the main harness from the engine compartment and they bolt together like a big plug, so you would have to detach the fuse panel and join those plugs then run the wires to the new location and reassmeble the fuse box, or substitute it with a suitable upgrade. If you are going to go through all that trouble you could run it into the rear compartment and put it in the center glove compartment or the jack compartment....
Race Director
Joined: Oct 2019
Posts: 10,735
Likes: 63
From: Deep in the Pisgah National Forest
I followed the diagram and the wiring does look confusing. As I told Yadkin, I'm just going to replace the corroded fuse panel and rewire the whole car. I made so many changes in how it works, it will be an aggravating job, but it will be neater in the long run.
I also would like to move the fuse panel out of the wormhole it's in, so I can get to it with the seats in the car. Do you have any suggestions or know anyone who has done it? I'm 72, 80% Viet Nam disabled, and busted it up from a motorcycle wreck 19 years ago.
Thanks for your Suggestion Rescue Rogers.
I also would like to move the fuse panel out of the wormhole it's in, so I can get to it with the seats in the car. Do you have any suggestions or know anyone who has done it? I'm 72, 80% Viet Nam disabled, and busted it up from a motorcycle wreck 19 years ago.
Thanks for your Suggestion Rescue Rogers.
That car has the battery in the trunk so that's where my new generic Painless Wiring panel will go. I will route the wiring bundle in a sheath, grommet through the the front of the trunk then through the console to the dash, and use an existing grommet to the engine bay.
For the C3, the battery is behind the driver's seat and there is a nice big area behind the passenger seat. Lay the seat down flat and you've got decent access- remove it entirely to build. In my '81 the computer is in front of the battery and has a big bundle of wires running from it to the dash and engine, so GM already did that work for you.
Melting Slicks
Joined: Apr 2001
Posts: 2,030
Likes: 363
From: Lubbock Texas
I wonder if you would have room to mount it on the firewall in the engine compartment? That's not exactly a weather resistant location but a company named Polycase makes some waterproof enclosures that might work out well.
https://www.polycase.com/waterproof-enclosures
DC
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Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,113
Likes: 9,241
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
What do you think you will do...rebuild it in place or relocate it? I may look at doing some changes this winter if I have some extra cash.
Thread Starter
Heel & Toe
Joined: Feb 2020
Posts: 18
Likes: 6
From: St. Marys Georgia
It's too much of a hassle considering the overall condition of most of the fuse holders as well. I've purchased a new 21 circuit (modern) fuse holder and wiring harness to replace it with. As I said at the beginning of the thread, I have replaced the original A/C/ system with a vintage air unit. It takes up what little space I have left in the passenger side dash.
I had hoped to install the fuse holder and wiring in the Jack storage compartment behind the passenger seat. But when I stretched out the wires I found I would have to splice almost every wire to the front of the car and the dash. That would give me exposure to many bad connections, it isn't worth the risk to relocate it to the rear. I'm still looking at mounting the fuse block to the firewall where the "old" A/c components stuck into the engine bay. I have looked up some waterproof boxes on Amazon that would house the fuse box and avoid exposure to water hazards.
I'm going to place the fuse block there and stretch out the wiring from that point and see what I have.
I had hoped to install the fuse holder and wiring in the Jack storage compartment behind the passenger seat. But when I stretched out the wires I found I would have to splice almost every wire to the front of the car and the dash. That would give me exposure to many bad connections, it isn't worth the risk to relocate it to the rear. I'm still looking at mounting the fuse block to the firewall where the "old" A/c components stuck into the engine bay. I have looked up some waterproof boxes on Amazon that would house the fuse box and avoid exposure to water hazards.
I'm going to place the fuse block there and stretch out the wiring from that point and see what I have.
Thread Starter
Heel & Toe
Joined: Feb 2020
Posts: 18
Likes: 6
From: St. Marys Georgia
I have Picked up a polymer 6" x"6" x 6" electrical junction box from lowes which had no holes in it and a gasketed, 4 screwed fastened lid. I drilled a 1" hole in the back, a 1" hole in the side to face the dsitributor and a 3/4" hole in the bottom. I picked up grommets to fit the holes and divided the wiring harness into what I need inside the cabin, what goes to the engine and alternator and what I need for my relays and lighting. I am now replacing one circuit a time with the new wiring. Ny the way the fuses are easy to get to and no more wiggling under the dash. I will post some pictures. I installed 4- 30 amp circuit breakers on the fire wall with the relay case to go next to the fuse box. I'll shoot some pictures and post them with a little more detail when time permits.
Thread Starter
Heel & Toe
Joined: Feb 2020
Posts: 18
Likes: 6
From: St. Marys Georgia
Update on the wiring on my 75 vette. Finished the tail end wiring, finished the lighting. engine and windshield wiper wiring. Moving into the cabin now (what a mess of wires). Hoping to get it done before November 9th, having surgery on my right eye and will be on light work for a while afterward. When it is completely finished I post some pictures. I appreciate all of your guy's suggestions and comments.
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
You could likely visit some junkyards to get some other engine bay fuse boxes from other cars, might be able to get some cheap if the yard really has no need for them.
What about putting the fuse panel in the rear storage area where the jack is stored?
Make the glove box easily removable and then install it behind it.
But keep this in mind, the fuse box should be rarely accessed at the end of the day. So a super convenient location is never really a huge consideration, just so long as it is serviceable is to be considered satisfactory. Just a thought....
What about putting the fuse panel in the rear storage area where the jack is stored?
Make the glove box easily removable and then install it behind it.
But keep this in mind, the fuse box should be rarely accessed at the end of the day. So a super convenient location is never really a huge consideration, just so long as it is serviceable is to be considered satisfactory. Just a thought....
Thread Starter
Heel & Toe
Joined: Feb 2020
Posts: 18
Likes: 6
From: St. Marys Georgia
I have removed the old fuse housing and wiring bulkhead connectors already. I have mounted a new 6"x 6" x 6" waterproof polymer box, with gasketed lid on the firewall on the passenger side. Cabin wiring is through a hole I drilled in the back of the box and firewall, where the original a/c unit was. The new engine and front lighting wiring are run and terminated. The rear wiring, including the backup camera, is wired and terminated. Now working on the cabin and dash wiring. which is a big job. I'm making a word document interpreting the original wiring diagram as script. I'll post it when finished.
But I do appreciate all feedback and ideas, thanks "Goody".
But I do appreciate all feedback and ideas, thanks "Goody".