The Stovebolt Site Forums The Shop Area The Electrical Bay Battery disconnect needed?

My meter shows a drain on the battery while parked. That normal? No accessories on line.

If on the 1942, no, that's not normal. If you're looking at the stock ammeter, possibly the needle has been tweaked toward the discharge side. Have you connected a real ammeter (like a Fluke Multimeter) inline at the battery to see what it shows?

Not normal. Nothing on a 1942 truck uses power when the truck is turned off.

Keep your meter connected and then go around the truck from one circuit to the next disconnecting items one at a time until you see the drain stop. Then you'll know what circuit to start checking for frayed wires or bad connections or whatever.

I'd start with the ignition switch / circuit. Disconnect the hot wire to the coil. Maybe it's staying on when the key is off and sending power to the points. Check them to make sure they aren't burned. Check the coil to make sure it isn't getting hot.

A disconnect switch would just mask the problem. You don't want a faulty circuit to start a fire. I suffered a total loss electrical fire 4 years ago while driving. Not something you want to have happen with your truck

My Fluke 77 reads 99.7 ma on my 42.
I Will check ignition next. Nothing else is wired in except a new regulator/generator which is charging normal.

That is a *lot* of current for an off state.

As a point of reference, my 2004 Denali with all the permanately powered computers and memory and stuff draws less than 1mA with the ignition off.

You have something fairly significant drawing current.

I agree with Jason. The spec for my F250 7.3L is 50 mA or less when everything is asleep.

When you say new regulator/generator, if it's actually an alternator, it's very likely that a diode has shorted and the battery is trying to power the alternator as a motor. That'll drain the battery in short order. It may still charge the battery normally.
Easy to check. Pull the power wire off the generator and see if the draw goes away.

I stayed with the original generator.

Possibly a sticking relay in the voltage regulator. There's one that's supposed to cut off the wiring to the generator with the ignition off.

A sticky cutout relay will discharge the battery in a matter of minutes, and probably smoke a lot of wiring in the process. Does the ammeter center itself when a battery cable is disconnected?
Jerry

I'd be real surprised if the ammeter would show the difference between zero amps and the reported 0.0997 amps.

Only moves when charging

But on a side note unrelated to your issue, my '37 has a battery cutoff switch, I use it for anti-theft and battery saver. I have purchased two batteries for the truck since 1999 and one was a Walmart. I shut it off every time I get out no matter where I am or how long I will be staying.

I found it !!! 6 volt + from the fuse panel was attached to the fuel gauge without a sending unit attached. I've got 0 Ma. drain on the batt. now. I'll need to get 6v B+ from ign. Switch if I use the fuel gauge.

Thanks for everyone's help. That miswire was my oops.

Good deal. Thanks for letting us know that you solved it.

Well done, grasshopper.