I've got a 1960 Pontiac parisienne (Canadian model), a few weeks ago I lost my taillights turned out the fuse blew. Replaced the fuse and had no issues for another week. Taillights and brake lights are out again (turn signal s work), fuse is good. Took out the headlight switch (standard 8 pin gm switch) and replaced it with a new one knowing that they go bad all the time. Still no taillights- and now there don't appear to be any dash lights, but the head lights and parking lights are still working. Could the new switch be a dud? I ran a jumper from the 12v in to the brake lights on the connector plug and they came on. Did continuity on the brake light switch and it's good. I also did continuity between some of the pins on the switch and it seemed like no matter the switch position there was never any continuity between the main power pin and the tail light pin. Any ideas??
On my gm switch the tailight wire was not pushed all the way into the switch connector block. Could that be your issue?
My suggestion in addition to above, inspect your wiring, I've had instances where the wire cover had cracked and was grounding out against metal, shorting the light. frayed wire at the break was also causing problems. Bulkhead connectors corrode - pull yours out and check for that inside the pins. If corroded, vinegar/lemon juice cleans the br*** connectors nicely. tighten the female connectors if they're loose. I had to separate the wire connectors from the pin housing to do this, but it solved a number of my issues on my 64 Chrysler.
A few years ago I ran into 3 bad brand new headlight switches, from 3 different parts houses, and 3 different companies! The 4th headlight switch from the 4th parts house and the 4th different company worked and still functions today. Yes, new parts can be bad right out of the box, and its been happening a lot more often these days. Unfortunately, just because something is new, it no longer means its good! All that said, on a 1960 car, I think I would want to take a good look at the condition of the wires, The insulation on the wires deteriorates over time, and that insulation has been there a long time. Another thing to look at is the taillight grounds. Back then most the time the lights were grounded through the screws that held the taillight housing to the sheet metal. Time hasn't been very kind to many of those grounds either.
So when you say that the turn signals work, do you mean the rear turn signals work? If they do, the wiring from the turn signal switch to the brake lights is good. What connector plug did you run the jumper wire to? Was it the connector at the turn signal switch or the connector on the brake light switch? The tail lights are powered from the headlight switch, but the brake lights are powered full time.
On my old Chevy turned out to be the turn signal switch, sorry to say. As old as your car is it could be the harness.
I would have someone watch the tail lights while you crawl from front to back inspecting every inch of the harness, and violently wiggle as you go. If that p***es, the get violent on the switch to see if anything changes
Thanks for the feedback guys, I haven't been able to get back to the garage since I posted the question. At first I thought the wiring back to the taillights and/or a ground was the issue but when I put 12v to the taillight plug on the connector I had my lights back leading me to think it's likely a bad switch. But... Does the power for the taillights come from the same source as the headlights? I could have sworn that power for the taillights comes from the fuse box then to the headlight switch (compared to the 12v for the headlights that's unfused) if that's the case I may need to get into the dash and/or run some continuity to the fuse box from the headlight switch
On a 60s vehicle don't the headlights have their own circuit going through a rectifier or circuit breaker where if the lights short out the headlights will dim out but not fully extinguish? Tailights should be on their own circuit.
Start at the bulbs and sockets in the rear and work your way forward. Through the years I have found all kind of stuff from melted solder on the bulbs to insulation worn away. Don’t start at the front it will just lead you down a rabbit hole. Put in a new fuse, turn the lights on and start checking things.
This is correct. Check the condition of the contacts in the fuse box also, I seen several where a clean up there cured a lot of issues.
You guys need a toner tool. Hook transmitter end to the light switch, then run the pen along the wire bundle till no tone. That will be where the problem exists.
Another place to look is bulk connector from main harness to rear harness. I believe it's in or around the drivers kick panel.
So I might have confused the **** outta myself but here's where I'm at: Made a bunch of jumpers so I could hook up the switch without plugging it into the connector, with the jumpers hooked up just like the connector there's no taillights or brake lights (obviously). Then I put a jumper from the headlight 12v power over to the the pin for the fuse box power for the T/L and everything worked. Next I checked for 12v from the fuse box to the switch and low and behold it has 12v, checked at the brake light switch it also had 12v! Then, for the sake of being through I put the headlight power to the brake light switch and it worked. Knowing I have 12v from the fuse box I hooked the jumper from that spot on the connector to the taillights and nothing. Put that lead to the brake light switch no brake lights, but I did have 12v on the output side of the brake switch. Nothing is making sense. I haven't checked the reverse light switch (those aren't working either) but from the diagram doesn't look like it would have any effect. The last thing I can think of is an issue inside the fuse box but that still doesn't click because I have 12v coming out
Also, I should add that the car is Canadian and the Chevy wiring diagram is much more accurate to the car for whatever that's worth
Dirty or worn contacts inside the turn signal switch can cause a lot of problems, would be worth a look.
Sounds like you may have a voltage drop in the power feed to the brake lights. You said you had 12 volts available at the switch. What happens to that 12 volts when you step on the brake with all wiring, no jumpers, connected? Based on your last comments, I'll bet it drops to near zero.
Alright, I heard you.... LOL. You have to be methodical when troubleshooting electrical, jumping around only confuses things. You're actually dealing with three separate circuits, each with its own fuse so it's probably not just one thing going on, and I'll get to that if it is. I hate full-car wiring diagrams, they always give me a headache.... I don't think this is a light switch issue, so to start re-connect it to the harness. As you've said that the head/park lights have worked all along, power to the switch is good. This incoming power doesn't come from the fuse panel. There should be two wires from the switch going to the fuse panel. With the switch on, one of those should be hot and is identified as Dk Green on the posted diagram. This wire feeds both the taillights and dash lights, each of which has it's own fuse in the panel. The other wire is dash light power returning to the switch to connect with the dash light dimmer. The taillights don't directly connect to the switch but are fed from the fuse panel on a Lt Blue wire. Check both fuses to see if they're blown, but don't replace them just yet. Do verify that you have power at the fuse terminals with the switch on. If you don't, that's part of the problem but not all of it. I expect you will find power. Next up is the brake lights. Again, the brake circuit is separate with it's own fuse in the panel. You say you've verified power at the switch on both terminals without jumpers, so if true that part is good. You'll check the rest of the brake circuit below. Last, the turn signal switch. Now when you say that they 'work', do both the front and rear work or just the front? Did both work, then the rears stopped? In any case, this needs to be checked to eliminate it as a problem. If either end lights up when the key and switch is on, that verifies turn power to the switch, again a separate circuit in the panel. If the rear turn lights operate as they should, turn off the signals and verify that you have brake power at the switch plug by pressing the pedal and checking for voltage. Remember this wire. Unplug the switch, and check for continuity between the brake power and each other wire with the switch off. You should find two that it reads to, and those two should read to each other. Remember those wires also, as those are the wires to the left and right rear. lights. Can't find this? Then you have a defective turn switch. Don't plug it back in just yet. Lastly, a check to see if the wiring to the rear of the car is damaged. First remove all tail/brake lamps from the housings. If these are the kind that the socket pops out of the housing, remove the lamps and reinstall the sockets. Carefully inspect each socket ***embly for bare wire or other possible grounding issues. Under the dash, check each rear turn/brake lamp wire for continuity to ground at the switch plug on the harness side of the connection. Do the same thing at the load side of the taillight fuse at the panel. If any read anything less than open, there's damage somewhere in the harness feeding the lights. That could also include why your back-up lights don't work. It could be it's pinched somewhere, maybe a trim screw has worn though, or it's just rubbed against a sharp edge too long. In any case, you'll have to trace the harness starting at one end or the other until you find and repair the damage. I suspect this was the original problem, any other issues are probably the result of this. But this procedure has checked for all of them. Good luck!
My guess is that you have a harness worn thru and at first made the tail light wiring short out, then open up the circuit. This is what probably has happened with the backup lights too. As far as the brake lights, my guess is that the problem is in or near the turn signal switch.
Steve: About the only thing that might be missing is how to determine if the wiring is open. A good way is to first remove the bulbs as you mentioned and if meter reads high resistance (no shorts) then reinstall good bulbs and check the meter for low resistance. If still high resistance then there is an open in the circuit. Could be anywhere from fuse panel to bulb socket. This is where a toner helps tremendously.
You are correct of course, I'll claim tiredness and a headache from that damn diagram as my excuse. I gave the sequence I did because while a simultaneous failure of both the head and turn switches is a rather large coincidence, it's also not outside of the realm of possibilities and if the trouble was found there, that saves the trouble of possibly removing large chunks of the interior to gain access to that piece of the harness. But the fact that he's blown multiple taillight fuses also points at a short and could also account for a damaged turn switch. The chance that all three of those wires have burned 'open' is small, but again not an impossibility. One thing I did learn after doing electrical troubleshooting over a 35+ year career is you don't want to ***ume that the first fault you find is the only one...
Okay, so looks like I got it figured out! It ended up being the back up light circuit, the previous owner had the switch wired differently than the diagram, most likely when the car was swapped to a TH350. Pulled that fuse and everything started working, now I'll go through the actual back up light circuit to find the specific culprit. @Crazy Steve thank you for the T/S help but one note, this car, though it is a 60 Pontiac it was built in Canada and because of that it's a Chevy in everyway except the sheet metal. The taillights/brake lights are powered from the fuse box to the light switch
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