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MG MGB Technical - Car won't start (not mine)

A friend of mine just called to say his '73B (Sven, correct me if I'm wrong) won't start anymore.

This is what happened: car drove beautifully all day, despite the warm weather we're having over here. Sven arrived at the Belgian equivalent of the MOT and all of a sudden, the car won't start anymore. The red indicator light doesn't glow anymore as well.
Jump starting the car didn't work either.
Lights however do still work

Any ideas as to what could've caused this would be appreciated!

Thanks in advance,

Alex
Alexander M

Hi Alex.

My first suspect would be the ignition relay (if it has one).

Does the engine turn over ?.

If it doesn't, is there a 'clunk' when the key is turned to the start position ?.

Do the wipers work ?.

Don
Don

Alex. Had a similar problem two days ago. The connection from the ignition light to the alternator had come loose (brown/yellow wire) and the alternator was not recharging the battery, nor was the ignition light coming on. Not noticed when I started the car in the bright sunlight.

We got the car started by pushing it and the battery had sufficient charge remaining to operate the lights and get the car home, but at significantly reduced speeds.

If that is not your friend's problem, the others are bad starter, bad battery, bad connections to the battery, bad connection from the battery to starter, bad connection from the battery to ground or bad connection from the engine to chassis (ground strap).

I charged the battery, then went checking system voltages from the battery forwards until I found the loose connection at the alternator. Hope this will help. Les
Les Bengtson

I also had a similar problem a while back. First, make absolutely sure the battery is charged -- bright headlights are a good check, so it sounds okay. Next, what sound does it make when you turn the key? If there's a clunk from under the passenger side floor, then the solenoid is engaging and my guess would be a bad or stuck starter. You can search the archives for lots of ways to fix the later. If there's no clunk under the floor, but there's a click from the passenger's side of the engine compartment, then the ignition relay is working but the starter solenoid is not engaging; check the solenoid contacts and, if they're all good, my guess would be a bad solenoid. In other words: replace the starter. If there's no click or clunk, though, your ignition relay has problems, in which case you should check the connections to it and, if necessary, replace it.

If it's the starter or the solenoid, you'll be able to pop the clutch to start it. I don't know about the ignition relay, but I'd suspect so.
Chris St. Pierre

Alex,
I had a similar problem a few weeks ago and traced it to a loose plug from the ignition switch to the dash wiring harness (must have worked loose from a knock from my left knee). Tightened and fastened with electrical tape to keep it from happening again.
Steve
Steve

You don't say whether it cranks but won't start or won't even crank, but as you mention no more ignition light I'll assume the latter.

If the lights still work, and continue to do so when you try to crank, power from the battery must be reaching the body and the browns at the solenoid. No ignition relay on a 73, so the cause of no ignition light and no cranking is quite likely the ignition switch, or the multi-way plug connecting it to the main loom by the steering column (as per Steve).
Paul Hunt

This thread was discussed between 27/05/2005 and 05/06/2005

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