QuestionI have a 1977 MGB I had a problem with everything on the green wires, fuel gauge,temp. gauge, brake lights, etc. Since I put it away for the winter I have removed the dash to repair a rip in it, now with the dash repaired I am putting it back and now when I start the car or just turn the key on it blows the fuse on that same line? I am not sure what to check except to disconnect one thing at a time and try the circuit?
Any suggestion would be greatly appreciated.
Thanks
AnswerHi Mike,
There is no way I can tell you what wire is shorted but I can tell you how most mechanics work on a problem like that.
As most mechanics do, I have made up a test lead with a circuit breaker in it and I put it across the fuse clips in place of the fuse so I don't keep blowing fuses while testing.
Yes, you do need to remove all the green wires and connect one at a time until you get to the one that causes the fuse to blow. You can probably purchase a 12v 35 amp circuit breaker from a place like radio shack.
Connect up the green wires that are ok and leave the shorted wire disconnected and note what don't operate. Then look at your wiring diagram and see where that wire goes. (most likely the dash) (look at the mounting points of the dash that you had apart to see if any obvious wires are pinched)
If that is not what is wrong pick only ONE of the items that don't work and use the diagram to start testing with an ohm meter or a powered 12v test light. I like to start at the load (item that does not operate) and follow the diagram back toward the operating switch or what ever turns it on and on to the battery. If you follow this method, you can NOT fail to find the problem. If you don't have a diagram, let me know and I will put one up on my web site for you to copy.
Howard
