[jeffcoslacker]

It sounds like you have a shorted battery, low charging voltage or a failing engine or chassis ground to me.

I'd first make sure the battery cable clamps are tight and clean. Then if the battery has caps, pukk them off and check water level in them. If it's dry, get a new one. It's cooked by now. If it's full, and you detect a strong sulfur odor or notice faint smoke from one or more cells, it's shot.

Even if it appears ok, I'd still have it load tested (most parts stores will do this free)...and at the same time they should be able to test charging voltage while running.

Check the opposite end of the neg battery cable to be sure it's tight and the ground surface is clean. There's probably a bunch of ground wires on one of the thermostat housing studs...make sure they look clean and undamaged.

If you are comfortable that the battery and cables are good, sometimes I'll try connecting jumper cables to the neg battery post, and the other ends to the engine and body, thus providing a secondary ground path. sometimes the demons disappear when you do this...then you just gotta figure out where the bad ground is (broken chassis ground strap, etc)

Also try moving the battery cables and primary wiring around while it runs...this will sometimes show you where a short or bad connection is...it may stumble or stall while doing this.

I've seen a lot of vehicles with bizarre multiple electrical symptoms like this that were because of a simple cracked battery cable clamp or a battery that had and internal short (happens if part of the grid corrodes so badly it breaks free and contacts the adjacent one...)