[s-cars] Burned battery cable

[ron kirkham]

S-heads,

I went out after work last night to fire up the 93 S4 for the trip home and
had zero action upon turning the key.  I had no dash lights, no interior
lights, no stereo, nuttin.  The ignition switch is relatively new, so I did
not suspect that.  Pulled the rear seat and see a pretty scary mess.  The
little plastic cover over the positive cable has MELTED.  The red cable (the
medium sized of the three) is black from the terminal post back about a
foot.  The shielding on the black cable is brittle as far as I can feel on
it's length.  The very small guage wire is toast as well.  The terminal post
on the battery had become hot enough to slightly melt the plastic case
itself and wiggle around in it's now enlarged hole.  I grabbed the wires
right at the terminal/post and moved them around a bit.  In so doing, there
was a small audible (not visual) spark and the interior lights came on.
I was able to nervously start the car and head home after throwing the seat
bottom in the trunk.  After turning the car off at the house, it re-starts
fine, but is parked util I can figure this out.  Started this morning
also.

Questions.  I'm assuming the heat was due to corrosion within the wires
causing alot of resistance?  The terminal post area does not have any
corrosion at all, but is now covered in melted plastic, so it's tough to
tell for sure.  Could this heat be caused by a bad or old battery?  The
battery is 3.5 years old and is a NAPA Gold.  It has been a little sluggish
in the mornings lately, so probably on it's way out.  What else could be
causing enough heat in this area to do this?

I'm thinking I need a new battery and new positive battery cable.  KATE
seems to indicate this is a three wire harness.  One wire to the starter,
one to a junction somewhere and the little wire not indicated where it
goes.  Anyone have experience on this replacement?

Anybody got any other ideas as to what might be going on?  I did install a
McCullough HID kit about two years ago, but other than that, no electrical
work.

As always, any help appreciated.

Ron Kirkham
93 S4 229K (crispy)