Need Electrical Help
Thread Starter
Instructor
Joined: Aug 2020
Posts: 182
Likes: 2
Need Electrical Help
I have a 1975 coupe which I have taken the interior apart to repair/replace all trim, dash and seats.Since I have it all apart, I wanted to fix a couple of electrical items that were not working. I guess after 45 years, a lot of people have had their hands in it. My problem is I have no idea what harness the issue would be in or how I would go about fixing them. I am not sure if they may all be connected in some way. Here are my issues:
1. No courtesy lights . Nothing happens when door is open or headlight switch is turned.
2. Seat belt alert not working
3. Key Buzzer not working
4. Light and switch in rear storage compartment not working
Any help would be greatly appreciated.. I am new to this and would like to have them working. Car is going into shop for paint, interior ready to go, but I would like to get these issues fixed before I reassemble
1. No courtesy lights . Nothing happens when door is open or headlight switch is turned.
2. Seat belt alert not working
3. Key Buzzer not working
4. Light and switch in rear storage compartment not working
Any help would be greatly appreciated.. I am new to this and would like to have them working. Car is going into shop for paint, interior ready to go, but I would like to get these issues fixed before I reassemble
Melting Slicks
Joined: Feb 2018
Posts: 2,295
Likes: 702
From: Marietta GA
1. Check fuses, ensure they are the correct size/amperage
2. Inspect fuse block for corrosion if fuse is ok.
3. Obtain a wiring diagram to see is all the problems are connected on the same circuit.
2. Inspect fuse block for corrosion if fuse is ok.
3. Obtain a wiring diagram to see is all the problems are connected on the same circuit.
Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri
I presume the battery isn't installed but if so disconnect the negative connection before doing these things.
Sounds to me like the entire CTSY (courtesy) circuit is dead. Check the fuse. If good clean the fuse terminals.
There was a recent post about the rear convenience lamp. THOROUGHLY clean the switch and lamp contacts!
Does the cigarette lighter work? If not check the CTSY fuse and even if it's good clean those contacts as well.
Sounds to me like the entire CTSY (courtesy) circuit is dead. Check the fuse. If good clean the fuse terminals.
There was a recent post about the rear convenience lamp. THOROUGHLY clean the switch and lamp contacts!
Does the cigarette lighter work? If not check the CTSY fuse and even if it's good clean those contacts as well.
Thread Starter
Instructor
Joined: Aug 2020
Posts: 182
Likes: 2
I presume the battery isn't installed but if so disconnect the negative connection before doing these things.
Sounds to me like the entire CTSY (courtesy) circuit is dead. Check the fuse. If good clean the fuse terminals.
There was a recent post about the rear convenience lamp. THOROUGHLY clean the switch and lamp contacts!
Does the cigarette lighter work? If not check the CTSY fuse and even if it's good clean those contacts as well.
Sounds to me like the entire CTSY (courtesy) circuit is dead. Check the fuse. If good clean the fuse terminals.
There was a recent post about the rear convenience lamp. THOROUGHLY clean the switch and lamp contacts!
Does the cigarette lighter work? If not check the CTSY fuse and even if it's good clean those contacts as well.
Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri
Also since you have the interior removed it's the perfect time to give the fuse box a good cleaning! Remove all fuses and "battery power" connectors. Get some spray electrical contact cleaner. Use it very liberally along with a small and fairly stiff stainless steel wire brush followed by a brass wire brush. Even with dash out the fuse box isn't the easiest to access so if you want to do a really good job remove it. There are two screws on the cabin side and one bolt (7/16") dead center of the big electrical connector on the engine side firewall. The box still won't move a lot so take pictures of the cabin wiring harness BEFORE removing as I've read that proper positioning is utterly critical to replacing the dash. In the '68-'77 years.
Sounds like you have a fairly optioned car so it likely has the courtesy delay function. If so the crude mechanical delay "module" is buried behind the dash. If it even works it's certainly due for replacement. Check the vendors for a modern solid-state update.
Sounds like you have a fairly optioned car so it likely has the courtesy delay function. If so the crude mechanical delay "module" is buried behind the dash. If it even works it's certainly due for replacement. Check the vendors for a modern solid-state update.
Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri
Sorry for the double posts.
I doubly suggest you give the fuse box a VERY GOOD cleaning.
The medium to small orange wires you find throughout the cabin are power for the CTSY circuit. That circuit is the one most messed for aftermarket stereos and other accessories that require constant power. They're also the most likely to get yanked hard and possibly breaking a wire (likely at one of the many factory splices). Said splices while secure use steel that can corrode which causes overheating under high load (think added accessories). Not sure about yours but in my '79 some of those splices were in the same harness position as ground splices and the scanty insulation tape used around the splices had fused together.
I doubly suggest you give the fuse box a VERY GOOD cleaning.
The medium to small orange wires you find throughout the cabin are power for the CTSY circuit. That circuit is the one most messed for aftermarket stereos and other accessories that require constant power. They're also the most likely to get yanked hard and possibly breaking a wire (likely at one of the many factory splices). Said splices while secure use steel that can corrode which causes overheating under high load (think added accessories). Not sure about yours but in my '79 some of those splices were in the same harness position as ground splices and the scanty insulation tape used around the splices had fused together.
Thread Starter
Instructor
Joined: Aug 2020
Posts: 182
Likes: 2
Sorry for the double posts.
I doubly suggest you give the fuse box a VERY GOOD cleaning.
The medium to small orange wires you find throughout the cabin are power for the CTSY circuit. That circuit is the one most messed for aftermarket stereos and other accessories that require constant power. They're also the most likely to get yanked hard and possibly breaking a wire (likely at one of the many factory splices). Said splices while secure use steel that can corrode which causes overheating under high load (think added accessories). Not sure about yours but in my '79 some of those splices were in the same harness position as ground splices and the scanty insulation tape used around the splices had fused together.
I doubly suggest you give the fuse box a VERY GOOD cleaning.
The medium to small orange wires you find throughout the cabin are power for the CTSY circuit. That circuit is the one most messed for aftermarket stereos and other accessories that require constant power. They're also the most likely to get yanked hard and possibly breaking a wire (likely at one of the many factory splices). Said splices while secure use steel that can corrode which causes overheating under high load (think added accessories). Not sure about yours but in my '79 some of those splices were in the same harness position as ground splices and the scanty insulation tape used around the splices had fused together.
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Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri