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MG MGA - Starter problem

1588cc engine -original starter and flywheel - single battery (12.5 volts) - starter (push button + separate solenoid) barely turns the engine. Is this telling me the motor is on its last legs ?
Roger Walker

Have you checked all connections are good, including earth from battery?
Graham V

Have you measured the battery voltage while cranking? If it drops below 10v, it could point to a poorly battery...assuming it's fully charged.

Also see if you can check the voltage at the starter when cranking. If it's much lower than the reading that you're getting at the battery when cranking, you may have a high resistance connection somewhere between the battery and the starter.

As Graham said, it could be a faulty earth connection - either at the battery, or at the engine. I'm not sure where the engine earth lead is on an MGA. One way to eliminate an earth problem is, assuming you have a set of jump leads, run a jump lead from the battery earth to the engine, or even to the starter body.

Also check that the starter mounting bolts are tight.
Dave O'Neill 2

Dave, Graham, I had assumed the leads were still good having changed the battery - hence the question about the motor but I will run the tests with the jump lead ( a good idea) and I suppose the voltage on starting in case the solenoid is faulty.
Results when it stops raining and I can get the car out.
Thanks - Roger
Roger Walker

Jump lead test successful - revealed a fault in the negative line with with a faulty battery isolator. The system is negative earth.

Interestingly the battery voltage while cranking was 9.5v.

Help appreciated
Roger
Roger Walker

Good news you sorted it easily!
Graham V

This thread was discussed between 24/03/2024 and 28/03/2024

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