QuestionRegular lights front and back work! Left and right rear signals and brake lights do not work! Hazard lights[4way flashers]work! Ground checked and OK! All fuses OK! Have Haynes manual, but wiring on car does not match what book says it should be! HELP!
AnswerHi John. My factory workshop manual for the MGB only covers cars made up to 1975, but it has 18 different wiring diagrams.
You have a 1974 MGB made for the USA market (Diagram #17).
Fuse #3 in the main fusebox supplies power to the brake lights, the turn indicators, and the fuel and temperature gauges. Do these gauges work? If they have stopped as well, then fuse #3 is faulty, or there is a bad connection at the fusebox.
Fuse #3 has 2 push-on connectors, attached to it. One connector is a single Green wire for the gauges. The other connector has 2 Green wires powering the brake lights and the turn indicators. If the gauges are still working, then the connector is faulty.
For your information, the hazard warning system uses the same turn lamps, but a different power supply, so that it will continue to operate after you remove the ignition key.
