[ischmitz]

ouch..... depending on what gave he might have fried some vital components such as the DME, the alternator diode pack, the central informer, the alarm module and/or other electronic modules required for the car to run. Most electronic modules have some rudimentary form of protection but still suffer damage when reverse voltage is applied.

It really all depends on how strong his battery was and how well it "pushed" against the incoming jump-start cable voltage. How long were the jumper cables in place until he noticed his blunder? Did the other engine idle or was it reving pretty good. What kind of jumper cables - pretty beefy or regular?

Check fuses and let us know what happens when you turn the ignition to ACC and to ON. You should see some instrument lights and such. If you are lucky it took out the fuses for modules on Terminal 15.

Ingo

Ingo