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MG MGB Technical - Broke down today!

Ignition light came on,fuel guage,temp,wipers all stopped working although engine continued running.I possibly touched the wiring/terminals around/near the two round relays mounted on the inner o/s front wing.What are these for? Could they be the cause? All seems to be working ok at the moment. PS. mgbgt 1979 is the model,RHD.
g swash

Loose wiring to the ignition relay, or the relay faulty itself. This is one of the two relays you mentioned, the other is the starter relay, unfortunately the wiring to each is similar.

The ignition relay has white, white/brown, brown and black wires and clicks on and off as the ignition is turned on and off. The starter relay has white/red, brown/white (or a different white/brown), brown and black wires and only clicks as the ignition switch is turned to crank.

UK cars powered the coil and the ignition relay from the ignition switch, and everything else including the ignition warning light from the relay, which is why the engine continued to run when the relay releases. When the relay releases with a running engine that will cause the ignition warning light to come on but all the other ignition powered stuff to fail. The fuel pump should also be on this circuit, meaning you shouldn't be able to run for long before the carbs run out.

American cars are wired quite differently.
Paul Hunt

This thread was discussed on 22/11/2009

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