The Stovebolt Site Forums The Shop Area The Electrical Bay slow constant discharge

i have a twelve system in my '51 pickup which seems to have a power drain somewhere.anyone have any ideas on where to begin?

Clean top of battery with baking soda and water - use paint brush for scrubbing. Make sure cell caps are tight.
Electrolyte plus dirt = good conductor.

Hook an ammeter in series with battery to confirm "leakage" when shut down. Could also us a lite bulb.

Dan Bentler

You may want too check the base of the battery isnt on bare metal. During restoration of a Freinds Ferret Armoured Car it was noted By the Army that the batteries resting on the bare metal actually discharged so they put 1/2" rubber mat under them

I think Dan has the right idea for finding a "small" power drain. I use a test lamp (looks like an icepick) in series with the disconnected battery lug and negative post. If you have drain the lamp will light. The brighter the more drain. I then start pulling fuses until the light goes out. This will get you to the ballpark of the problem. You might also consider pulling the big wire from the alternator, just watch the light. BTW, I've always been told that a battery sitting on metal or concrete would discharge it. I've read recently that's a wives tale. Who knows???

Batteries used to be able to drain through the case. The cases are made from different materials now and don't have that problem.

i attached the alligator clip to the battery hold down bolt and the bare neg. side of battery and the light lit up like a christmas tree.the positive terminal was connected.forgive me i know little to nothing about wiring or any of the associated problems, but i am willing to learn.also forgot to add that when i disconnected the battery wire from the regulator the light went out.

Sounds like you've alrady got a clue to where your problem is. I'll leave futher troubleshooting to the guys who are up to snuff on generator/regulator problems other than to ask if the regulator points are stuck together. Good luck.

OK so something in regulator ie a contact is not opening up. Pull cover and with deegnerized check for free movement on all contacts / linkages. The next step ie checking for grounded coil requires a VOM. I am going to switch you over (oh that was bad) to one more familier with these regulators.

Dan Bentler

Trhamilton, You should check past posts for information on checking your regulator. There might be model/year specific information which will help you find youy problem quickly. I always switch over to an alternator setup with internal regulation as it reqires less parts, less wiring, and cleans up my firewall. Dan, I always use the neg. for this kind of testing as it is the ground side (usually). So if I move a wire against a ground I don't get a big spark and don't have to go change my underwear (if I'm wearing any).

Cant argue working on grounded side of battery better. Boring maybe but for sure better

Dan Bentler