DaveM said:
Nope... The battery clamps are probably OK. There is a chance that the
heavy cable from battery negative to chassis (or engine), or the cable
from battery positive to the starter or starter relay is loose. Check the
connections on the other end of those wires. If they're tight and clean
(not corroded), then they are likely not the problem.
That said, there's a 99.97% chance that you've damaged the car's
electronics (computers). Your ECC (Engine Control Computer) is the guy
that controls almost everything under the hood. If he's dead, then your
car is essentially dead.
Haul or tow the car to a *qualified* service facility for a thorough
diagnosis. If it's the ECC, make sure your Master Card and/or Visa are in
good standing. Judging from your description of events, the car might be
beyond economical repair.
--
Regarding your original problem, as others have suggested, a bad ground (-)
connection at the battery or where the battery cable is bolted to the car's
frame would cause the symptoms you described... intermittent non-starting,
dim instruments. Or a ground fault elsewhere. Ground faults are a bastard
to diagnose, they could be caused by a wire's insulation having rubbed off,
a poor connection, a broken solder joint, corrosion inside a wire's
insulation which can't be seen. I have worked extensively on older cars'
electrical systems, and it takes some serious patience AND LOTS OF TIME
generally. I'm not saying that it definitely won't be a quick fix, just
mentally set yourself up for the long haul. That's why people in the know
shudder when you start talking about an intermittent ground fault problem...
and that's why it's generaly at least a few hundred bucks when you bring
your car to an auto electric specialist.
As far as hooking up the battery backwards, you can get a pretty good
indication of whether it's electronics or wiring by doing some simple tests.
Honk the horn. Turn on the headlights. These are generally both NOT wired
through the ignition module or ECC and should work if the battery is good
and the wiring is intact. If they DO work, that means any fusible link or
main fuse is fine, and that your problem is most likely with your ECC or,
hopefully, a fuse which controls the ECC. You can often buy salvaged ECC's
from online junkyards, you need to be EXTREMELEY SPECIFIC with the model
number... pull yours out and job down the exact model number. Different
models and/or years of the same car have different engines or features that
the ECC controls, so they are very specific to the particular year and model
of vehicle.
