This is for a 1967 F-250.....was running fine, then one morning, no power whatsoever....

Checked battery and it read 0.32 volts, disconnected it from the truck and it immediately jumped to about 3.5 volts.

After recharging battery, reconnected it to truck, got a spark as i connected the terminal......noticed, with keys OFF, my aftermarket Tach was showing 2000 RPM and gradually dropping as battery drained.

So, swapped coil - same thing

Disconnected points/tach from the coil - **strange part** - when I reconnected the positive terminal this time, the engine began trying to turn over....

No burn wires visible.....with everything off, I'm reading at least a 0.5 volt load on the battery.....

Seems I heard before a bad Voltage Regulator would try to make the alternator into a motor.....is this what's happening? How to test?

Any clues?

 

I don't know what ".5 volt load on the battery" means. Load is measured in amps. If you want to measure the load on the battery, you have to take the neg meter lead off the battery, put your meter in amps mode, and hook one lead to the disconnected battery neg, and the other lead to the battery negative terminal.

You can also use a testlight like a crude ammeter. Hook a testlight up the same as the meter(between the neg wire and the neg terminal) and if it lights up bright, then you have a drain.

Once you get setup to measure the drain, then you just start disconnecting things till the meter reading drops or the testlight goes out.

 

Well, got out to test each circuit this morning, with test lamp, from the batt side connections on the solenoid.....and, this morning, nothing is drawing any power.....

So, Hooked everything back up and started it up, was getting 14.16 Volts at the battery......but, after a 5 or 6 mile errand run, began running a bit funny.....stopped and tested the battery, only about 12.75 volts, but would slowly climb if sitting at idle.....letting it cool off to do another test run to the auto electric shop....lol