HELP!! Alternator / battery question

[DangerinMaine]

So I posted a thread the other day regarding a cable & battery changerover/replacement, and got some info.....I frig'd up, put the cables on backwards......long story short, now I have a spark on the negative terminal.....even with everything (powered) off. I don't have a spark if the alternator is unplugged.....is my alternator bad?????Help, need this to be a quick fix. Thanks in advance all, I received a lot of help on my last thread.....

 

[COPPERHEAD85]

Alt. is probably toast.Hopefully you didnt cook the ECM.
Auto Zone will check the Alt. free on or off the truck.I would start there.

 

[DangerinMaine]

Swwweeetttt, I'll check it out....I figured that might be it, but wanted a second opinion....thanks again....

 

[COPPERHEAD85]

Your welcome...............I hope nothing else is cooked.

 

[GoodOld85BlueBalls]

make sure you mark all the wires this time before taking them off. A digital camera is great for before and after shots while doing work.

 

[adsm08]

Yeah, you may have cooked the regulator, something may be shorted through, something may just be screwy. Run a second ground from your frame to the battery and pray that your PCM isn't cooked.

 

[snake]

Sometimes a little spark is normal. Did you try to start it and does it run?

 

[Bob Ayers]

A battery connected backwards will short the diodes in the alternator. The PCM has an internal diode clamp for negative voltages on the 12V lines (switched and unswitched) which will usually blow the PCM fuses to protect it. However, large positive voltages will destroy the PCM, and any other electronics( GEM, etc.).