Jump start cables wrong way round. Help!!

[mac391]

ello,,

i left my '96 mgf on the drive for months and battery went flat. i charged it up with the battery from another car running, only i got the leads mixed up and left it running like this for about 10 mins till everything started smoking..
What's the worst scenario in terms of damage i have caused?? The leads up to the starter motor look burnt out!!

 

[Burnerman]

At the very least, new starter leads and a new alternator mate
John

 

[Peter.N.]

As John says the alternator will no doubt have short circuit diodes, if you are very lucky that may be all, but it depends on how much electronic equipment your car has and how well protected it is. I doubt the alternator is worth repairing as it may well have cooked the windings, so fit a replacement and see what else doesn't work.

 

[wotan]

Also anticipate ECU damage, if this is the case it won't be cheap.

Wotan