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MG MGB Technical - electrical problem

I have a 1980 GT and when I tried to start it kesterday I turned the key and NOTHING. No click, no ignition light, absolutely nothing seemed to happen. headlights are bright and do not dim when key is turned.
Has anyone got any idea where i should start looking for the problem.

Maurice
M Irwin

Maurice. The headlights being on would seem to indicate that it is not a battery problem. Headlights and horn working together would definitely indicate that it is not a bad battery or bad connections.

The power flows from the positive terminal of the battery to the main terminal of the starter solenoid. From there, a brown wire goes to the ignition switch. With the ignition switch in the start postion, power flows from the ignition switch to the starter relay (this is the one rearwards of the fuse box). Therefore, I would check for power going to the starter relay from the ignition switch. If you have power there, check for power through the relay to the starter solenoid terminal. If you do not have power to the starter solenoid, check backwards to the switch and the brown wire powering it. A copy of the wiring diagram, preferably expanded to about 300% is a significant help in tracing electrical problem. I had mine laminated so I could trace circuits with a water soluable marker. Les
Les Bengtson

Hi Maurice.

It sounds like a problem in 'the brown wires' or the ignition switch.

The power is getting through to the starter motor (the lights wouldn't work otherwise), but isn't making it between the starter motor and the ignition switched circuits, which include the starter motor solenoid feed and the alternator's indicator feed.

It isn't a fuse problem.

Don
Don

Hi Les.

We were both typing at the same time, but you got to 'submit' first !.

Where has the 'electrical help' section gone ?.

Don

Don

No ignition warning light implies the ignition switch or the supplies to/from it. Check the multi-way plug by the steering column is pushed fully home, and check the brown for 12v all the time, the brown and white for 12v when the ignition is turned on, and the brown, white and white/red for 12v when turned to the crank position.
Paul Hunt

This thread was discussed on 13/02/2005

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