New to the forum. Looking for help as I am not an idiot to the automotive repair world, but my ignorance hinders me from doing everything myself. Not very good at asking for help. I will attempt my best to explain issue and what has been done. Looking for a starting point to check and get it fixed right. Sorry for long post but wanting to provide all info that I know to better help me get the correct answers.
I purchased an early 77 for my wife as her 20th anniversary gift. She is a car woman and always wanted one. Knows what to appreciate. Giving her something she always wanted, almost as much as me, put a smile on her face that nothing could remove. Current issues still have yet to remove the smile. 383 ci, 350 auto, 3000 stall. Runs great. Only issue knew about the car from the previous owner was needing repainted. Still not sure her suggestion (War Bonnett Yellow) is right for the car, but whatever she wants. It came with new parts such as badges, window seals, door seals, trim pieces, and much more.
The problems I have encountered were with the wiring. I noticed repaired wiring on the ac/heater harness when I went 7hrs away to test drive and buy. I was told there was an issue, but it had been "fixed by a friend". However, there were other issues that I noticed after purchasing and getting it home that I missed during the test drive.
1. Neither the rear side markers nor the 4way markers would light up when the lights were turned on.
2. Dash lights did not work. Only the Left turn signal marker was illuminated when the lights were on. Which I know was wrong.
3. Headlights would come on but would not raise up.
4. When I attempted the left turn signal, both front turn lamps under the head lights would flash. Appeared to be the same brightness. LR tail light would blink brightly as should and the RR would blink faintly. Same if I attempted the right turn signal.
5. IF I turned on the headlights while testing the blinkers, they would stop blinking all together.

I fixed issue with headlights raising as the vacuum line from intake split to also run door on the heater. Found that a line there was not even connected, and the vacuum wouldn't hold.
Assuming there could be an issue with the turn signal switch with evidence of it being removed at least once. As well as the harmonic plug looked distorted. Replaced the switch with a new one, but still had the same issue.
Attempting to test the wires for power from the plug to the front and rear, replaced the 4 side marker pigtails as they were all bad. I do seem to have power showing up on the test light on the right side marker wires at the harmonic plug when the left turn signal is activated. Same with the right activated. Further digging, I found bad wires between the bulkhead connecter that had been cut and spliced. Evidence of getting warm/fire?, they spliced them by twisting in another piece of wire and wrapping in tape. 7 wires were done this way. 3 going to the turn signals and headlights. Asking around, some suggested a ground issue. I had read about that being a common problem. Thinking that is why there was evidence of current in both sides of the plug, I tested all the grounds that I could find. BAT to frame, frame to block, the two on the core supports, one under dash on driver side and the rear lighting to the frame. All seem to check fine with light and ohm meter of 0.02 to 0.06.
Still enraged about my ignorance not allowing me to see the issue, I talked myself into rewiring it all. Not a bad thing. I think it is good move with 50yr old wires, how many "friend fixes", and the appearance of heat or fire at one point to some wires at the bulkhead. But I think I should have done more research and ordered a different wiring kit. Especially, since I don't enjoy wiring or know a lot about it. Was talked into a painless kit. OK. Not that expensive, and it offered up all options currently needed, and the additional options for the future with extra circuits already there. Just more work on my end instead of a new factory style that could just be plugged in and done. I kind wished I looked harder. Anyway.
Fast forward 5 weeks of normal work, side projects, and trying to wire a car. Never done it before. Lots of time looking through the AIM, factory wiring diagram, and the Painless book that came with kit. I have all the wiring done with the exception of the security wires (wasn't going to put back), horn (which came to be missing completely under the hood and the peg and spring in the steering column), and the dome light that was not there. Also, I have not replaced the socket connecters on the front or rear turn signals as they are not here yet. Should be here today.
I also wired in a separate ground block from Summit to help with any grounding issue. Or I am hoping it will. All lighting wires, wiper switch, etc. are on the central block. Replaced all the bulbs and new sockets for the dash lights to replace the bad or missing. New headlight switch as the piece that connects the ground for the dome light was broke off. New NSS as it didn't work in park, so the previous owner bypassed it.
TEST time..... And would you believe I have the same issue as before. Only difference is now that all the bulbs and sockets behind the dash for the tach and speedo are new and work, both turn indicators are on when the headlights come on. Still the same "bleeding" issue with just the turn signals themselves. And the front 4-way lights still don't work. The rear side markers do blink when the turn signals are on. Not sure they are supposed to do that, but not a concern of mine. And, if the headlights are on, there is no flashing of any turn signals or indicators. I can't remember if it is the same if I engage the hazards or not with or without headlights on. I am still leaning to the conclusion that the new turn signal switch must have something wrong with it. But I could be mistaken. Assuming that the only reason for all the lights on when the switch is to the left only is it is sending power to all. Maybe not all 12v since they are dimmer on the rear. I checked all the wiring 3 times before attempting to hook up the battery for the first time with new harness. Am going tonight to start checking it again. Probably start with pulling steering wheel again and checking the new switch. Any info that could point me into the direction to remedy my issue would make my wife even more happy than she already is. Loves driving the car, hearing the up-turn nosed comments about the loud rumble of the straight pipes until the new exhaust is put on, and stepping on the throttle to drown the sound of the haters as she showers them with tire smoke and and her ****eating grin. Thankyou in advance for any suggestions or help.

 

I can appreciate what you are going through. Bad enough it's an old car, but undocumented wiring changes and missing parts are the pits. If you have the official factory shop manual with wiring diagrams and circuit operation descriptions, plus a good multimeter you are well armed. I think you are on the right track but make sure you document what you are doing and take pictures for yourself before and after a repair. Just work on one circuit at a time and keep an eye out for corroded connections. Some spray electrical contact cleaner will help too. Best of luck!

 

I'd rather swap the heads than chase wiring problems! As the members said...clean all the harness grounding points. Corroded grounds caused most of my wiring problems. There are several body-to-chassis grounds you need to check/repair.
Double check the voltage coming out of the column harness connector after all the grounds are repaired so you will know all the bulbs and switches are receiving proper voltage.
START with the running lights first and repair as needed.
Then deal with brake light problems.
Then deal with headlight problems.
In other words...repair the simplest system first

Let us know how the simple repairs turn out before you begin ripping out the dash!

Document/Pics/Document/Pics !!!

 

Thank you Bigredwing and doorgunner for the responses. With your ideas, solution was found.
After work, i tackled the grounds again. Double checking them that they were in fact getting good connections. Appeared to be good.
Then I checked the voltage in and out of the turn signal switch and was good.
Decided to start with the front parking lights first. Simplest circuits as you guys suggested. Started at the front because the back only seemed to "bleed" to the opposite side the turn switch was activated. But the front, both seemed blink the same brightness and that seemed odd. As well as the fact that the new 4way lights did not work.
Upon first inspection, it appears when the previous owner painted the car, he allowed the paint to spray on the bulbs painting them blue. It also got on the connectors themselves. Going to take out the bulbs and check the connections inside, it was difficult to get the bulbs out of the sockets. I was thinking the paint build up was keeping them in. Got them out and the connections looked good and the voltage was there. Grounds were still showing good. Upon inspections of the bulbs for paint build up on the casing, it appears that the owner had the wrong bulbs in the front. They were single filament bulbs. And that was not letting me get the bulbs out. I believe the casing was jumping between the two connections in the sockets and causing the power to back track into the turn signal switch and the indicators that were both showing as soon as the parking lights were turned on. Same thing when the turn signal was switched to either side. Double checked and cleaned the sockets for the front, added new bulbs from my 76 K20 that should be the same, and the lights magically started working correctly. What I have noticed, after finding out that the last 2 months are the result of $2 worth of bulbs, is I seem to have a level of patience that just barely exceeds my level of aggression against myself for something so simple and it was not caught at the start or checked thoroughly. Wished I had done it better, but, the car now has all new wiring and the wife seems to be happier. We learn and move on with the help of good people and ideas in this forum. Thanks again. Now, on to the next project.

 

Thanks for a well-written explanation which will help others.
"Who-da" thought.........................wrong bulbs painted blue!

 

I will admit I actually did that "wrong bulb" problem to myself on a car years ago. Swore to never rush a job and do that again.