Brake light/turn signal issues.

[Arethius]

'70 Dart custom.

So last Sunday, I was driving over one of the bridges here in the tampa bay area and had my left rear tire tread blow off the tire at about 80mp/h. Thankfully, it was a steel belted radial so it kept pressure but it knocked a hole into my (admittedly rusty) trunk floor slicing the rear wiring harness pretty good.

So I crimp and splice the wires back together matching the colors that was there and replace the fuse that was blown in the process.

Now currently, my left light functions completely normal. The right light only comes on when I turn on the headlights. Interestingly enough, the right turn signal doesn't turn on at all when the headlights are on but will when off although the rear light doesn't flash with the front.

I was thinking it might have popped a filament in the bulb so I just replaced that today but there was no change.

Can any body offer me any ways to go about diagnosing and repairing this? I haven't had a chance to dig into the wiring diagram yet but I did download it so I have it available.

 

[67Dart273]

This sounds like a grounding problem. If you cannot do anything else, solder grounding pigtails onto the lamp socket shell and ground them.

Make certain also that one of the bulbs did not get the filaments welded together. Best/ quickest way to check is simply buy a couple of spare bulbs.

 

[harrisonm]

Do you have a circuit tester? If not, get one. The $8 ones at Harbor Freight work OK. I totally agree with 67Dart273 that is sounds like a grounding issue. If you do have power going to the socket, a good bulb will light up if properly grounded. To check that, use a circuit tester to see if you have power going to the socket. If you have power and the bulb does not light up, check the bulb first. That is easily done on the car battery with jumper wires with alligator clips (an in-line fuse on one of the wires is a good idea). If the bulb is bad replace it (obviously) and start over. If the bulb is good (and you had power to the socket), a bad ground is the most likely problem. Try using a jump wire from the socket to a known good ground. If there was power to the socket and the bulb was good, I bet it will light up when grounded. If there was NO power to the socket check your splicing and wiring.