QuestionQUESTION: My 1980 MGB which previously had a problem with no instruments/signals/brake lights - solved by replacing the ignition relay - now has a new problem.
The running lights (rear, sides, etc) do not all work. Only the front left come on. Brake lights and signals are okay.
I thought it might be a bad ground and have found a couple that were dodgy but it still has not solved the problem. Any ideas?
ANSWER: Hi Ron,
The running lights (parking lights) and the side marker lights are on the same circuit so if your rear lights are out you need to turn on the head lights and go in the trunk on the right hand side and start testing the connections for power on the red wire coming from the forward harness. When you loose power on the red wires you loose tail lights, license plate lights and side marker lights.
If you had a bad ground wire at the tail light assembly you would loose turn signals and brake lights too.
Don't just look at a bulb to see if it is good, test it with power to see if it lights up and use a test light to test the socket.
If you don't have a diagram let me know and I will post one on my web site for you to copy.
Howard
---------- FOLLOW-UP ----------
QUESTION: I found the problem!
I checked at the fuse box to see if power (green/red) was reaching the top two fuses that control the markers. Power was reaching but was coming out for only one. The output tab for the other was not any good. I put the wire for that on the spare tab from the other fuse and the lights all worked. (Except for one but that was just a dirty ground).
Ahh Lucas, you little imp!
AnswerYou shouldn't disrespect Lucas by referring to him as a "little Imp" He commands respect as the "Prince of Darkness". and when he teamed up with "Opus" to make the "Opus/Lucas" ignition system he earned the additional title of "Duke of NoSpark".
Howard
