Fried ECU?

[oplix]

I was jump starting my car and accidentally crossed positive to negative and negative to positive. The wires started to burn. After I got them off, I thought that it was ok because I started the car. Everything was fine like my stereo and everything worked. I put my window down and started to drive to a store. On the way to the store, my battery started dying and eventually went completely dead. I pulled at a gas station and someone jumped me. I barely made it home. By this time everything that was electrical was pretty much dead. I looked at the battery terminal and pulled the positive wire off. I noticed that the crossing had blown a piece of the metal terminal off the battery and the positive wire connector. I had to jump it again with a different set of wires just so I could pull in but I couldn't put the window up and the power locks didn't work.

My question is if everything was fine right after the whole mess up with the jump start, how likely is it that my ECU could be fried now? I know it's a vague question considering I have to replace the battery. Since there wasn't anything out of the ordinary as far as warning lights except for anti lock and SRS (probably due to the battery going dead), is it still possible that the ECU will need to be replaced?

 

[93_tsi_fwd]

I did the same thing to my brothers 91 gst 2 years ago. everything was fine until the battery drained out. The ECU was still good, but the alternator went out, and the wire harness melter and some wires touched. The problems were all the light bulb went out, no elactrical stuff worked except the ingnition cause it started. (radio, windows, head light, tail lights etc etc.. didnt work) I suggest go throught your harness and check for melted wires.

 

[oplix]

so was all the electrical problems coming from the harness? Did the alternator go out completely or was it just the connectors?

 

[93_tsi_fwd]

Yes, all the problems were comming from the harness. and the alternator was fried. we parted it out and swapped all the goods to a gs shell(1g)

 

[steve]

I've had to replace the "protection" diodes before when somebody reversed the polarity.

I'm sure you have blown the alternator fuse and may have toasted the alternator itself. The car isn't charging so you ran the battery down driving it.

Get a good charge on the battery and see if the car starts. If it does you shouldn't need to replace the ECU but it's a good idea to bring it by sometime for a quick check.

 

[oplix]

bring it by where?

 

[Blitz_86]

you might have also killed the battery swapping the lead can kill the cell, but i would check all the fuses first. cause i have fried some fuses working around the alt and grounded out the hot wire going to the alt popped some fuses

 

[oplix]

oh i know the battery is dead cause i blew a piece of the terminal off.

 

[oplix]

Ok I replaced the battery and cable connectors and everything works perfect. I also blew the 100a alternator fuse so I replaced it as well. ECU was not damaged, wire harness ok, alternator works as far as I can tell.