Earth lead comes off battery cause damage?

Likely to blow some bulbs. Radio? Tachometer? Or with luck none of these.

It can do nasty things to the alternator...

John

I've run a car with no battery on just the alternator for quite a while with no apparent damage - jump it then drive it somewhere.

I can see how it *might* cause problems but it should be limited to the regulator getting hot...

It might cause damage. It might not. It largely depends on how much the alternator regulator depends on the battery to smooth off the voltage spikes and how sensitive the car electronics are to those spikes.

Christian.

The message from "PC Paul" contains these words:

So've I, but I've also had it happen and toast the alternator. Down to design and luck, I suppose.

But the OP had minutes earlier posted in another thread that he was having problems with his alternator. Now I'm no Sherlock Holmes... ;-)

John

This happened to my Mrs car. The earth strap sheared while she was driving it. It hesitated momentarily when it happened (at least she thinks it happened then, when she went over a stick and it must have bounced up), then when she stopped and removed the key it wouldn't re start.

New strap cured that it and there didn't seem to be any lasting problems.

Nothing.

If there are def no electronics such as ignition / fuel injection / instrument panel etc, probably the worst you'll do is fry the alternator.

Tim..

Yep. Any number of electronic devices in the car which previously did something might well start to do nothing instead.

Cheers,

Colin.

Utter rubbish.

Oh dear. I see you're about as good at physics as you are at admitting when you're wrong.

Please don't make me explain alternator load dump to you *again*.

Cheers,

Colin.