Chasing source of battery drain

[Willard M.]

If my 56 sits for a week or more the battery is flat unless I use the battery disconnect. If I disconnect the positive battery cable and connect a muti-meter between the cable and the positive post I get a reading of 12 plus volts with the key off and the door closed, indicating that there is a draw somewhere, correct? I then individually disconnected wires to the generator, then volt. reg, then relays, each time still finding 12 volts flowing. I then pulled each fuse, one at a time with the same result. I have pulled the wire to the clock, again with the 12 volt reading between the positive post and positive cable telling me that juice is flowing somewhere that I haven't found yet. I have an after market FM radio that also has been unplugged as well because I originally thought the station memory function would be the culprit. Am I doing this right? Any ideas for next step?

Bill #2659

[Loren L.]

Re: Chasing source of battery drain

I just went through this on my '64 El Camino; turned out to be a stuck voltage regulator.

[William C.]

Re: Chasing source of battery drain

The cigarette lighter is also an unfused circuit on those cars.

[Willard M.]

Re: Chasing source of battery drain

Thanks guys, I will try both tomorrow-just before I shoot it.

Bill #2659

[Verle R.]

Re: Chasing source of battery drain

After you shoot it I'll haul off the carcass for you.

Verle

[Bill D.]

Re: Chasing source of battery drain

Bill,

Your test proceedure is correct but the criteria is incorrect. You need to look at Amps not Volts when connecting your meter in series. Start by testing on 20A scale to be safe. You should not find total parasitic load greater than 100mA for it to be acceptable.

The only test to make on the Volt scale is surface discharge on the battery. Connect Neg lead to Neg post and touch Pos lead to battery case around the Pos post. Be careful not to touch the post! A reading greater than 0.5V indicates excessive surface discharge.

Hope this helps you find your problem.

[Willard M.]

Re: Chasing source of battery drain

Thanks for your help. I hadn't considered that I might be getting a drain right at the battery itself. This PM I will check that out although I am pessimistic because everything else seems to have been fruitless.

Bill #2659