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MG MGB Technical - Ignition left on - checking for damage

Hi,

When I went to pick my '66 GT up from the garage today after some work on the brakes I discovered that they'd parked up and left it with the ignition on. I don't know how long for, but the battery was totally flat and the coil was too hot to touch. After a boost, the car started and ran fine - I'm just wondering if there's anything I should check for to make sure no damage has been done?

Thanks,
Tim.
Tim Jenner

Tim. Normally, only points and coil might be affected. If they work now, they should continue to work, but a spare set would be nice to carry as a "just in case". Les
Les Bengtson

Les,

Thanks, that's good to know! However, I have Lumenition Magnetronic electronic ignition installed and not points. Apart from physical damage and checking that it still works, I guess there's not much else I can do. I was not impressed with that garage yesterday...!

Cheers,
Tim.
Tim Jenner

Ah, electronic trigger, eh? In that case I trust you are already carrying points and condenser as a spare ...

If the coil was hot then the trigger was passing a continuous current, and it may have been overheated as well. The way electronic components are life-tested is at higher temperatures than 'normal' as this shortens their life in a known way. You have been warned.
Paul Hunt

Yes, I do carry points as well! I know all too well about the weakness of electronics to heat (my background is in electronic engineering). It would seem sensible to me for the static state of the trigger to be "off" rather than "on" - that way it would pass no current when the ignition is left on. Since it's a hall effect magnetic trigger, it will only switch when the engine is turning over anyway.

Tim
Tim Jenner

It may be a good ide to change toe coil, or at least, make sure you carry a spare to go with the points.

I know for a fact that the pertronix ignition will fail if the ignition is left on without the engine running. (Just don't ask me HOW I know this. BTW, it wasn't on my MG, thankfully)

When the pertonix goes, it really goes, spewing foul smelling goo all over your distributor.

(my coil looked like an old food can - bulged out.

It's life may be reduced, but since it works now, I wouldn't worry too much about it, other than to carry the spare points, which you are already doing.

Matthew Jones

Whilst full electronic system that send a pulse of high-voltage to the coil are only doing so when the engine is turning electronic triggers like Pertronix and others only replicate the points. If the magnet is within range of the pickup, or the optical shutter open, they will be conducting and passing current through the coil, which is why it got so hot.
Paul Hunt

This thread was discussed between 11/07/2003 and 16/07/2003

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