I have an 81 with a desmogged 20R. If I pull every fuse, the headlight relay, the taillight relay, and the heater relay, there is a 45mA draw from the battery. If I disconnect the voltage regulator, it still pulls about 25mA. If I pull the charge lamp relay too, it still draws about 2.5mA. If I unplug the thick white wire at the + terminal or at the alternator, with the aforementioned stuff connected, draw is zero. Referencing the wiring diagrams, we're talking about the B power source.

Is this normal behavior for a voltage regulator? How about the charge lamp relay (it's not a normal relay, but has a diode in it and I don't know how it works)?

What else could be drawing current? I've gone over the wiring diagrams (for an 83 and an 85), and the only thing left is the "cold start heater relay", but I can't find it or any wiring for it on my modified 81.

My electricals work 98% (the hazards are grumpy first thing in the morning, that's all, and I know the flasher relay is old and worn) - charge light works, battery gets charged, lights are bright... I just noticed a small spark when I hooked up my negative cable the other day, and got curious.

Im not a pro at electrics but if the truck runs good and the alternator keeps it charged why does it matter?

As long as there is no draw with the key out of the ignition and the doors shut who cares?

Well, there is a draw with nothing on, and it appears to be the voltage regulator. I'm wondering if mine is behaving normally.