copb8 97 Report post Posted January 5, 2019 My driver's side brake light and turn signal have stopped working. Passenger side is working fine so I assume it's not a fuse. I have a set of vintage LED's rear lights that have worked perfectly to date and I 'think' are working fine still. I used a 12v tester to poke into the rear light wires and it seems that I'm not getting any juice to the unit. I am detecting voltage on my running light wire so I know the tester is working. Where would you start looking for the failure in this circuit? Quote Share this post Link to post Share on other sites
fvike 173 Report post Posted January 6, 2019 I'd start with replacing the LEDs with the stock bulb. If both works, you know the fault to be in the driver side LED. Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted January 6, 2019 I'd suspect the turn signal switch as the first thing to look at: they are simply not very reliable. 1 lanky reacted to this Quote Share this post Link to post Share on other sites
copb8 97 Report post Posted January 6, 2019 If the front signal works would that switch still be suspect? Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted January 6, 2019 Yes. There are separate contacts for front, rear, left and right. Quote Share this post Link to post Share on other sites
copb8 97 Report post Posted January 13, 2019 Did a little more poking around today. I verified that the Vintage LED unit is fine and that I'm simply not getting power to it. I have a question regarding the suggestion that it may be the turn signal switch, I didn't mention originally that the brake light on that side isn't working it. With that information could the turn signal switch still be the culprit? Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted January 14, 2019 Brake light and turn signal are shared on the rear on one filament; running lights are on the second filament. So yes, the brake and turn signals are mixed on the turn signal switch; even more reason to suspect the TSS. Quote Share this post Link to post Share on other sites
copb8 97 Report post Posted January 14, 2019 9 minutes ago, Midlife said: Brake light and turn signal are shared on the rear on one filament; running lights are on the second filament. So yes, the brake and turn signals are mixed on the turn signal switch; even more reason to suspect the TSS. Yep, I get it now. I'll pull the steering wheel and run some tests. Thanks again. Quote Share this post Link to post Share on other sites
Floridastang 13 Report post Posted January 15, 2019 Here’s a thought, I had the same issue and completely disassembled the steering column and began to trace wires. After a few hours of standing on my head under the dash, which is a feat in itself for a man of my age, I decided to check to see if there was power at the socket. Guess what, there was and the bulb was good. Upon further inspection I discovered the the socket contacts were not oriented correctly and did not make contact with the bulb. I ordered a new socket form Midlife spliced it in and problem solved. Just a thought Quote Share this post Link to post Share on other sites
lanky 44 Report post Posted January 15, 2019 I've had such consistent problems with replacement turn signal switches I'm debating dumping the column switch for a turn signal button switch panel. I'm on my third replacement and none have lasted longer than a few drives without issues. They were purchased through different vendors yet look exactly the same. Quote Share this post Link to post Share on other sites
copb8 97 Report post Posted January 16, 2019 Lanky, any chance you have some type of issue with your steering column/steering wheel itself? Can anyone comment on the brand of replacement switch that has worked well for them? I was going to order the one sold by Summit. Quote Share this post Link to post Share on other sites
lanky 44 Report post Posted January 19, 2019 Well I pulled the column out when I did the borgeson swap (had to) and it looked fine to me. No excessive play or anything. My original switch worked for original 85xxx miles When my replacement switches, there are a few issues I've encountered: Self cancellers break, every one I've owned does this eventually...cheap plastics :( Contacts for horn button work intermittently, or honk while turning (due to poor design or lack of ability to center the switch...see below Had to file mounting holes on switch to properly center switch around column When wheel is installed loosely (wiggling still) switch works fine, when wheel is tightened securely either horn goes on or horn contacts make terrible scraping sound from bind, despite the use of dialectic grease (no it wasn't runny) I know I've purchased at least one SD brand one, one from npd, and I can't remember the other. I'm tired of spending the money on expensive switches that keep failing. For the money I could make a cool switch panel, some may hate this idea but I'm not trying to remain original. Quote Share this post Link to post Share on other sites
aslanefe 333 Report post Posted January 19, 2019 The aftermarket switches especially the canceling cam part is garbage. I am working on modeling the canceling cam (slowly) so I can 3D print it. I am thinking that I will have to modify the model to make it flexible enough but still work and last using the available 3D filaments. Quote Share this post Link to post Share on other sites
copb8 97 Report post Posted January 19, 2019 Spent some time troubleshooting today. Pulled the steering wheel and ran the tester on on the contacts. The Green-Orange wire is the circuit that's not working. I was able to follow the current all the way through the switch. I also used the right side (Orange-Blue) circuit as a test as it is functional. Best I can tell everything in the hub is working as expected. I then when down the column and disconnected the curved connector. The horn wire is always hot on the car side. I made a test wire with 2 alligator clamps on each side and clipped on end on the hot pin of the horn. I took the other end and clipped first to the Orange-blue of the passenger turn signal light and it came on. When I did the same to the driver signal light I got nothing. So it looks like I have some type of break between the column connector and the rear light fixture. I looked in the trunk and the wires look in decent condition with no signs of a break but that's not conclusive. I was wondering if there are any more connectors in the run of the wiring loom? From the wiring diagram I'm looking at it doesn't appear to be. I assume that wiring harness runs somehow from under the dash through the rocker panel tunnel and then up and over the wheel well. Anything to look for there? Quote Share this post Link to post Share on other sites
copb8 97 Report post Posted January 20, 2019 Ran a continuity test from the car side pin of the green-orange wire to the bulb pin of the rear light and didn't get anything so it looks like there a break somewhere along that line. Weird that it would just happen without anything else being done to the car. Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted January 20, 2019 There is a connector for the rear tail lights between the tail-light harness and the underdash harness. From 10+ years working on these harnesses, I would place more emphasis on a broken wire (probably twisted splice by a previous owner) than on the molded connectors. Most breaks in tail-light harnesses are in the door sill area where someone used a longer screw than necessary and pierced the harness. YMMV, but the above is what is more commonly seen. Quote Share this post Link to post Share on other sites
copb8 97 Report post Posted January 20, 2019 1 hour ago, Midlife said: There is a connector for the rear tail lights between the tail-light harness and the underdash harness. From 10+ years working on these harnesses, I would place more emphasis on a broken wire (probably twisted splice by a previous owner) than on the molded connectors. Most breaks in tail-light harnesses are in the door sill area where someone used a longer screw than necessary and pierced the harness. YMMV, but the above is what is more commonly seen. Thanks for this Midlife. A couple of questions. I need to find which run of the wire is bad. When you say there's a connector between the rear tail lights and the under-dash harness are you referring to the curved connector at the base of the steering column? Or is there another one? And if so where would I find it? I pulled the door sill and just visually the wire run looks intact and the wires are encased in some plastic conduit. Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted January 20, 2019 The connectors to the tail-lights are probably behind the driver's side kick panel or just above it. On a 69, there are two 3 pin plugs (flat---you want to look at the red one); on a 70 there's a red and white four pin plug (square). Orange/blue wire is right side light; green/red is left side light. Quote Share this post Link to post Share on other sites
aslanefe 333 Report post Posted January 20, 2019 Original wires on my 69 is not encased in plastic conduit under the door will, they are braided. I don't remember plastic conduit on my 70 either. To me, plastic conduit means someone has done wiring repair. Quote Share this post Link to post Share on other sites
copb8 97 Report post Posted January 20, 2019 Not sure if I should be happy or not. While digging under the dash and locating the 4 pin connector I was pulling and tugging and making sure the connector was plugged in well. I really didn't think I did anything but now my lights are working!! Of course I was skeptical that if I jiggled the wires again they'd stop working again but so far they haven't. I've pulled and tugged and wiggled the wires under the dash and everything is still perfect. So do I just count my blessings and move on? BTW, that plug is buried and a pain to get your hands on. Regarding conduit, car had a repaint and it looks like the conduit was added then. Quote Share this post Link to post Share on other sites
