Alternator charging issue

[patrickt]

Originally Posted by dcdoug

I was worried this might be the case and I'm thinking this might be it (sort of a dumb design). Here's my guess as to what happened:

Loose wire behind the dash (there were several I tightened, but none were super loose other than one of the leads to the panel lights dimmer knob), caused some of the other failures (solenoid, ignition switch, voltage regulator and ignition idiot light) and I'm hoping when I replace the bulb (all the filaments look good, but hopefully it's bad) it will all work.

The electrical design is really, really simple. One side of the light is fed off the ignition switch, the other side of the light runs to the voltage regulator. If the system is not charging, the connection at the VR will be grounded, and as soon as the system starts charging, that ground becomes 12v positive. That's why when you turn your key on, but don't start the car, the light is on, but goes off as soon as the charging begins. If you turn the key on, and the light does not come on, then something is wrong on the circuit.