[martinjbradburn]

I just replaced the battery in my FJ40. While hooking up the negative side one of the leeds from the alternator burned up.
I put everything back the same then had to pull it off to adjust and it fried.
Now I'm not sure what to do.
Should I replace the wire with a new one?
Here's another question: Does the negative usually have 2 other wires connected or is it the positive.
I thought I put it back the same way but now I am confused.
I am sure that I shouldn't try starting the truck without that wire.

[dfmorse]

Don't know how u did this. The neg lead from the battery goes to the frame, period; no other leads off this 4ga wire, unless u put them there for further grounding.

Any close up pics of the damage? Might be able to trouble shoot from those pics. In the stock configuration, there are multiple leads in heat shrink to the alternator. U may have to have the alternator tested; may have blown the rectifier pack in the alternator.

...

[Pin_Head]

If you hook the battery up backwards, it will fry the B+ wire to the alternator and it may fry the diodes inside. It is the positive wire that may have more than 1 wire coming off the cable end.

[martinjbradburn]

OK. I am an idiot.

The old battery I took out was so corroded you couldn't tell one end from the other.

So I tooka guess.

WRONG.

I switched the battery around and replaced the fried wire and now it runs fine.

I will watch to see if the alternator charges the new battery to make sure it works.

I could always put a meter on it and test it that way also.

You can't learn from your mistakes if you don't make them.