QuestionThanks for the quick response. New tail light refers to the whole tail light assembly, except the wiring - the car has been recently restored, and both tail lights were replaced. I was assuming the bulb came inside the tail light?
I can also tell you that with a wire probe meter with the light bulb inside, the light in the meter comes on when testing the right side wire when the headlights are on, but no response (light) on the meter when the turn signal/brake lights are tried.
Thanks for the good information - it should really help running the problem down. Rick
-------------------------
Followup To
Question -
My right side tail light does not work for brake light or blinker functions. The right side tail light does come on when the headlights are turned on, but it still won't blink or brake regardless of the headlights being on or not. The left side works fine for blinker and brake lights with or without the headlights on.
Also, when I plug the right side tail light plug onto the left side tail light, the left side does not blink or brake. It behaves exactly like the right side - comes on with the headlights on, but will not brake or blink. The right side tail light plug does not reach the left side, so I cannot try that.
Would you please give me a checklist of things to check/eliminate in the order you would try them? Should I start with a new tail light wire extension plug? The tail lights on both sides are brand new. Thanks.
Answer -
The tail lights are completely independent of the brake and turn lights - they are on different circuits, so the fact that the tail light works doesn't tell us anything about the turn and brake lights. The rear lights have a dual filament bulb in them - one filament is bright and is for the brake and turn function, the other filament is dim, and is for the tail light function.
Your symptom indicates that either the right side dual filament bulb has a bad bright filament, or else there is no 12 volts coming back to the right side of the car on the brake/turn wire - this is a separate wire which comes independently all the way from the turn signal switch in the steering column, so your problem is in the wiring that runs down the left side of the car, or in the turn signal switch, or in the bulb socket itself.
You say you have a "new" tail light - but I assume you mean new bulbs? If so, take the new bulb out and swap it with the other side, so that we know we have a good bulb in the right side. (Some new bulbs are defective, especially if they come from overseas, which most do these days).
If the bulb proves OK, get a test light probe and probe the two terminals inside the bulb socket. (Be careful not to slip and contact the side of the socket or any other metal part with the probe at the same time, else you will blow a fuse.
With the parking lights turned on, you'll see 12 volts on one terminal. With the brake pedal being pushed, you should see 12 volts on the other terminal. If you do, the problem is in the socket itself (not making contact with the bulb) or in the bulb. If you don't, the problem is in the wiring, as discussed above.
Dick
AnswerOK, thanks for the follow up. I want to emphasize that the fact that the tail light contact has power has nothing to do with the stop/turn contact - they are completely independent, merely sharing the glass envelope of the bulb (it should be an 1157, or it's equivalent, a 1034 or a 2157). Yes, I'd guess a brand new tail light would have come with a new bulb.
But the absence of 12 volts on the other contact (the one for the stop/turn function) indicates that the problem is in the wiring anyway, so you can forget the bulb considerations for now - trace that wiring - something isn't plugged into the right place somewhere!
Dick
