I have encountered yet another brake light problem, this one not as simple as my last..... First, when I press the brake, my dash lights go on (which are linked to the taillights). Also, when the taillights are on, the LEFT brake wire is always hot, causing the left brake light to be constantly on when the taillights are on. Lastly, when I turn on the RIGHT turn signal, both rear lights flash.. I ran a whole new taillight wire underneath the car to make sure the wires werent fused above the headliner.. but its still doing it. When I unhook the brake and taillight wires from the lamps, the dash lights dont go on when the brake is pushed. I know this sounds complicated.. but i really need help!!
Definately a bad ground at the bulb socket. The power is going through the filament, and then backfeeding through the other wire.
your taillites are probably where its malfunctioning. You want to test the sockets with both bulbs remove so theres no backfeed. Check that the sockets are both grounded well again without any bulbs in either. Also inspect you bulbs/filiments sometimes a bulb can burn out and the filiment will cross the other and cause a backfeed, but it sounds to me like one of your sockets aren't getting a ground and thats where the backfeed is. Also check front blinker\parking lites if you got'em.
The front blinkers work totally normal. I will try grounding the sockets better. Does the problem with the left brake wire being hot while the tailights are on relate to the bad ground in the socket?
I grounded the tailights better, but its still happening. It only happens when the right taillight is hooked up. The left brake wire is still staying hot when the tailight switch is engaged as well. i cant think of anything else to check!!
Do you happen to have a repair manual for your car that shows the wiring diagram? If so, you might want to carefully review the wiring setup again to make sure all is connected as it should be. Sounds as if something might have gotten crossed. One time, my headlight switch kept blowing its fuse and getting hot......I eventually found I had two wires connected to the wrong connector posts. Also, some people have made a separate additional ground wire for their tail lights.....to make sure they are well grounded to a clean, non painted piece of metal on the body. Just a thought.
Now I literally just have the brake light wires going from power, to switch, to taillights.. i bypassed the steering column for now. The dash lights still go on with the brake pedal, and when the taillights are on, the left brake light turns on. It must be somehow going through the filament in the tail lamps, but how?? i have them grounded really well.
I hope this doesn't come off as a smart ass responce. But you don't need internet advice on this car's electrical system. You need to either find some one knowledgable who is close enough to lay hands on the car. or Get in touch with Tugmaster here on the HAMB and order yore self a brand new wiring harness with some good instructions. Between this post and one of your previous post it seems that some thing is really wrong with the entire system. I just don't think that there is a quick fix here.
Im afraid you might be right Just trying to work with what I have based on the budget. I generally have a good grasp on wiring, but I was just stumped this time. I have learned today that electricity can jump through the filament, so posting here has helped a bit.
For what it's worth, do you have an aftermarket turn signal unit on your steering column.... I had simular problems with my Olds and it was about to drive me nuts.... I finally traced it down to a tiny contact that was bad inside the turn signal unit on the column, made my lights do all kinds of crazy things.
It's the factory switch, but i completely bypassed the turn signal switch and its still doing it. im going to try to ground the taillights even better and see if that fixes anything. Thanks for all the suggestions guys
Have you tried new bulbs? I once had a bad bulb that did bizarre things in an OT car. As a last resort, I replaced both bulbs and the problem was solved. Bob
I will try that next, bob. I found out that when i disconnect the "taillight" wire from the right lamp, the problem goes away.
Now you are getting some where! Isolating the problem to the right tail light, check every thing about that light. Good ground? The bulb socket is where the bulb grounds, but the socket can corrode between itself and the tail light housing. Check this. 60 years of ham fisted mechanics can do bad things to the socket itself. Look here very closely for internal shorts where the wires exit the socket, where the wires touch the spring, etc. The socket base can get twisted a quarter turn allowing the bulb contacts to create a bridge between them. The base getting twisted can create an internal short between wires just under the socket. Plus it will over time just get loose and create weird intermittant problems. Electricity in a car has 10,000 places where things can go wrong. In an old car you fix one then go find the next one.
You have a short between the left turn/brake wire and left tailight wire. You also have a bad ground on the right side tail/brake socket. Now when the tailights are on, so is the left brake. Also when the right turn is on, the power also goes through the right tailight filament (because of bad ground) and over to left tailight, which is shorted to the brake filament on left side, therefore flashing both signals. So take a test light, and with the left tailight/brakelight bulb out of the socket, test both the tailight and brakelight contacts at socket with the test light. (The test light must have a good ground!) To test the right hand side, just turn on the right turn bulb and check the right tailight wire to see if it flashes too, using the test light. Yuuup, Sold, Bam! Outta here!
this should help ya if it is a factory switch after 60 years sometimes it hard to tell what the old cotton wire colors really were, and if you get just 1 wire switched around it could also cause the same problems.....but still sounds like a ground/backfeed problem to me.
i'm tuned to this thread for futures problems with my 49 Pontiac coupe how are All the grounds on the sockets
It sure sounds like a ground problem to me. There are several places for the ground to be lost, sometimes it is easy to miss one. Tail light housing to body Bulb socket to tail light housing Bulb to tail light socket Filaments to bulb base Forty years working on trucks, I've come across all of them.
Look verrrrry closely at those items at top right and bottom right. Captions read "tail light/stop light"
Yes sir, it does, but where is the wiring to the tailights, parking lights, guess they are wireless, LOL. Without the tailight and parking light wiring, it may be kinda unclear to someone who isn't knowledgable with automotive wiring.
Well, I have some good (and embarrassing) news.. I replaced the bulb in the right taillight and all of my problems went away Thanks for all the help guys, I really appreciate it.
Sounds like your old bulb had gunk on the shell of the bulb (Ground portion) and was not making a good ground. But that still does not explain the left turn light coming on with the tailights on, unless you had the left turn bulb either wired wrong or installed backwards. HMMM!
look again at the top and bottom of the right hand side your taillites are there, they run thru the signal switch. Your rear blinkers and brakelites are the same filiment in the bulb. Its all good tho, the first time I tried to figure out how turn signal switch worked I think I was lost for days.....FYI the schematic should of labeled them "stop/turn" and showed a seperate line from the headlite switch going to taillites....sometimes you have to read into what they mean, certian terminology and functions have changed over the years. I.E. what we call front parkinglites, the use to turn off when you pulled you headlite switch all the way on
Sure it does. Power went to R/H tail light filament, it had no ground at the bulb so it traveled out through the R/H brake/turn filament on through the (centered) turn signal switch and on to the L/H brake light filament, lit it up and grounded there. Very common occurrence with a bad light or bulb ground.
When I was a young race car driver we used to haul my (ot) 67 camaro on a 47 ford truck. Well we wired up new tail lamps on the truck with the tail lights hooked up to the wire that was hot with the parking lights on. We got stoped for no tail lamps one day about dusk,of course when I stopped I shut the head ligts off and left the park lights on. The cop could of sworn the lights were not on,but they were now and we couldnt find a problem. He let us go and I had figured out what we had done and did not turn the headlamps on until we were out of sight! Had a little dumb repair the next day. Gary
You are correct. Funny that with the bad ground, applying brake will also illuminate both tailights (and dash lights), whereas applying tailights will illuminate left brake light. Ah, electricity, sure is fun stuff!
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