MGB Electrical issue- turn signals dim and cause the brake warning light to flash

[Jerry]

1978 MGB. When you turn on the turn signals, the brake warning light flashes and the lights are very dim. Indicating a cross wire somewhere. The ignition switch was just replaced in this car and the problem started after the replacement. I pulled the plastic column off and the ignition switch appears to have been installed correctly.
Is there any way the turn signal stalk has become defective and somehow is feeding back though the other dash system? When this car was dropped off at my house, he turned off the key and the engine turned off, but the dash lights were still on. We had to unhook the battery to shut them off.

Looking for ideas please.

Jerry

 

[JPSmit]

My first inclination - as always is to check and clean all your grounds. That said, I have had two related issues with the Midget. I did have to take apart the stalk and clean, not so much the contacts, but the whole face. Current was creeping. Also i have had to disconnect my brake warning light sensor because it made the starter run on. Never could figure out why, even after i removed the diodes.

 

[Jerry]

I was looking at the wiring diagram and I did find one loose wire this afternoon. A ground wire to the wiper pump. This ground is shared with other switches. So I will repair that and see what happens.

Jerry

 

[DrEntropy]

Good first step is as JP says: Check all grounding points. Electrons are lazy. If the grounding leg of a circuit has resistance it will go for the next available path. That is usually through lightbulbs.

 

[Jerry]

So the loose ground caused the turn signal issue, but another problem was left on the car. Someone had hot wired the car because the ignition was causing problems, or they so they thought. They installed a new ignition, but never took off the hot wire, so there was a hot lead going to all white wires, all the time. IE: the coil was hot, we were lucky it did not burn up the pertronix. all fixed now!

Jerry

 

[drooartz]

Well found, Jerry.

I haven't dug too closely into my Millie GT's wiring yet -- I'm partly scared of what I might find, and your issue is a reminder of what can be done to these poor cars over the years.

 

[DrEntropy]

Drew, yours is far less "complicated" than the later ones.

 

[Jerry]

Yea, after working on this 1978 with all the smog equipment and extra safety switches, I must say that I would buy an earlier car if given the choice. But it runs again! I was going to take it back to the owner today but driving in weather that will hit 99 is not fun. He can wait.
Jerry

 

[DrEntropy]

Well said, Jerry. :thumbsup: