77 Ford 150 battery Drain

change the voltage regulator

Why not diagnose .. ? OK maybe you know from experience that the regulator in that car tend to fail ?

Get a voltmeter, any cheap one will do.

Charge the battery w a charger.

Set the voltmeter to the 20 volts range and check the voltage on the battery.

Now start the car, take it to, say, 2000 rpm and check again. If it isn't higher than with the engine off, then the car doesn't charge, and then it could be the regulator.

If it does charge, then after a short while it should be 14.2 volts or something like that. Then, your problem is that something drains the battery even when the engine is off. I suppose one way to find that something would be to pull each fuse, put the probes of an ammeter where the fuse used to be and see if any current flows - that would indicate a dubious circuit.

Soren

Do the wires get hot as soon as you connect the battery, or not until you turn the key, activating the starter ?

Soren

Correct

Thanks

ok then it makes sense to check the starter :)

BTW, you really mean all the wires get hot ?? Isn't it really only the thick guy going to the starter ?

Soren

Here's the update thanks for all the help still in need!

Took Alternator in had checked found it to be BAD.... Replaced with new. (cha-ching) New Voltage Regulator... (cha-ching) With freshly charged NEW battery (cha-ching)... Engine hesitantly started and ran fine. Pulled Red lead cable off battery terminal and engine DIED... Battery now drained. Engine won't restart just turns over 1/2 turn then nothing. Suggestions?

This leaves me a couple of different things to check that I can think of...

Ignition Switch Short Starter Solenoid Short Open in the Alternator return path to the battery

latest update

Engine doesn't like to start but once started the voltage at the battery terminals is 12.40v and slowly drains about .01v every 10 seconds , indicating running off battery only and once turn off the battery is too weak to restart engine.

If the problem was in the starter, starter solenoid this would be consistent with a hard start but once started would have no effect on the battery drain. If the problem was in the alternator, voltage regulator this would be consistent with battery depletion but should have no effect on the starting.