Need Advice. Connected battery wires backwards and.....

[verde2002]

So yesterday while trying to jump start my 1971 2800cs I was distracted by a conversation and connected the booster cables backwards and didn't realize it until the alternator wire started smoking and the wire jacket melted. This all took about ten seconds. I waited a minute or so, reconnected the wires correctly and turned on the car but that only lasted about 30 seconds and car shut off on me. What is really interesting to me and maybe someone can answer this is now the car won't crank at all and more bizzare is the fact that when I have the key twisted all the way to the starting position it doesn't spring back one click like it should once car is on. The key twists all the way and stays there. Again the car won't crank, the "L" light stays on even though the key is not in the ignition and my passenger side power window stopped working. I did look at all the fuses under the dash and they were all good. Where should I loook? Which relays might have gone out? Why does my key twist all the way and not return a click like it should have?? Any help would be appreciated.

 

[x_atlas0]

Ah, I feel your pain. I am in the same boat, and I have been trying to fix it for the last two years.

At the bare minimum, you will need a new alt and voltage regulator. It looks like at least one of your switches melted, resulting in a constant-on state. On the plus side, that does seem to indicate an ignition switch problem. However, given the host of likely other faults this introduced, your (probably) only real option is to fully re-wire the car. New chassis and engine harnesses. Most of this stuff wasn't designed with a full opposite-flow current in mind.

 

[Arde]

Interesting. I cannot think of too many solid state circuits in the car that would be affected by reverse polarity. It must come down to the damage caused by overload currents. The switch and relays are a good place to start, and put Jay Mackro's phone number on speed dial, he seems to be cleaning up a similar mess on his 2800CS.