What can possibly do this?

[Caesard]

A little background info; i had to switch engine from my former tt to a new pristine shell (thanks Matt Wilkinson). When finished, had electrical gremlins in that my dash was lit up like a Christmas tree while driving. But could not find the cause, and didn't know the exact grounding points on the car to check if it was bad earth.

So one day, left the headlights on and went to play snooker. Came back and car was as dead as a doornail. Jumped it with someone's help and it couldn't not stay on under it's own power, so somehow managed to limp it home by throttling it all the way.

Took the battery to get charged the next day and was told the battery was toast.

So, i bought an Optima yellow top battery from ebay and put in it. But noticed that while the battery started the car, the voltage charge was slowly dropping (i have a voltage reader on my battery terminals).

On a whim, i decided to have a look at my alternator, and this is what i found:

 

 

 

 

 

Turns out that as i was trying to remove the screw holding the cable to the alternator, it was so badly fried the screw broke under the spanner

 

 

 

What could have caused this? Was it bad earth from the battery? Or what? If so, how do i earth the battery properly? Do i earth both positive and negative terminals?

 

All help appreciated. Am in South East London if anyone can help me have a look. I have bought a new alternator from Keron, but dont want this one screwed up also.

Thanks

[wile e coyote]

Personally I'd get an auto electrician in and not drive it

That could of ended in a fire

[mellonman]

i cant see the pictures at work but bad earths/contacts can cause arking where the electric jumps the bad part causing a ark this would get worse and worse over time

[Chris Wilson]

The alternator wasn't grounded properly and this can cause all manner of weird issues. As can oil inside the brush housing.