MG Car Repair: 1977 MGB, fuel gauge, temp gauge

Question
I purchased a 1977 Mgb with low miles, and was in storeaged for 15 years. Now that I have brought it out into the light once again, I have a continuing problem. Everything electrial works fine and then the tach, fuel gauge, blinkers,(maybe the temp gauge), Horn and tail lights will quit working. This will start and stop without any notice, or change in the running of the engine. The car has had a few changes to the engine, carb's are now weber's from Italy, steel headers for exhaust, no air pump, and just a muffler in the exhaust pipe. Not sure about the Horn I haven't tried it when the rest of the items were working? Where should I go from here? Thank you Rick

Answer
Hi Rick,

Any time you have an intermittent electrical problem with several items at once, you should try sanding and cleaning the fuses and fuse retainers.

It is close to impossible to locate a fault when it is not there, so you must test while it is in it's failed mode. (not working)

When it is in a failed mode take your wiring diagram and pick out ONLY one of the failed circuits and use your wiring diagram and a 12v test light to trace that circuit only from the load (item that failed) and go one connection at a time toward the source (battery) I always pick the simplest circuit first to trace.

This is a 100% successful method and you can not fail to find the fault. Most of the time when you find the fault, it will correct any other items that also failed.

If you don't have a wiring diagram, let me know and I will put one up on my web site for you to copy.

Howard