I have a '72 Mach1 that had a rough life before I got it. Somewhere
along the way it got a mid-80s 302 put in it, and the wiring's been
cut and spliced over and over. When I got the car it started reliably,
although if the battery was left attached it would get drained to
nothing before the week was out. I'm working around that
(disconnecting when not in use), but lately the car has been just not
starting. What seems to be happening is, on the weekend I'll hook up
the battery and notice the dome light goes on when i open the door.
Turn the key; it turns over and starts up. I drive it for about 10-15
minutes, then come back home and shut it off. I try to turn the key
again and nothing. No starter motor, not even a 'click' sound from the
starter solenoid on the wheel well. Open the door and the dome light
comes on as it should. Turn on the headlights and they light and don't
visibly dim after 30 seconds. Last weekend I tried checking all the
connections between the starter, starter solenoid, alternator, and
ignition on the column. Thought I had it licked when it started, but
same thing happened again. I've already replaced the alternator and
starter solenoid. What to do now? I'm hoping I can put off rewiring
the whole car until I decide what I'm going to do about the engine,
but I'd like to at least have it running reliably until then. Any
ideas?

Thanks,
    Neil