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Discussion Starter · #1 · (Edited)
I've got a boat load of accessories in my LS powered '56 Chevy...DVD, alarm system, a/c, power windows, door locks, antenna, speaker amp, electrically controlled air ride suspension manifold/switches, etc...

Complete new wiring harness throughout.

My battery goes dead after about 3-5 days of sitting (this is the 3rd new battery I've tried)

With my multi-meter on a 10A setting going from the negative battery terminal to the negative cable, I get a reading that fluctuates from 0.01 to 0.02 (initially the reading is at 0.18 for ~40 seconds, then drops to 0.01/0.02).

This is a pretty low (normal) amp draw, right? Shouldn't be enough to drain the battery in just a few days should it?

Any ideas what could be draining or killing the battery?

3,111 Posts
What kind of alt do you have? How is it wired? I had an issue once...... I replaced the old alt with a new int regulated one...... bottom line, I had reversed the pigtail wires and the battery would drain after 2-3 days.

Now when it did this the alt housing would get very hot because of the reversed wires created a direct short in the internal regulator.

When it was running all was ok because the internal regulator removed the ground (the gorund that lights the idiot light), when it wasn't running there was a direct short to the positive side of the electrical system etc....... check and verify that the pig tail wires on the alt are going to where they are supposed to go.

You are going to have to use more than your eyeballs here....... you need to disconnect the battery, unplug the alt pigtail, and verify the hot side of the pigtail (AKA the sense wire) has continuity with the pos battery cable.

Leave the battery disconnected and hook a battery charger up to the neg and positive battery cables, turn the key to on, then ground the idiot light side of the pigtail (AKA the exciter wire) ...... your idiot light should light. The reason I use a charger instead of the battery..... if it's hooked up wrong, and you ground the wire, the 10 amp on the charger will pop the charger's C/B instaed of frying your elec system.

654 Posts

You may have a component staying powered up that powers down when you disconnect the negative post.

If you are not already, I would use a shunt ( like a knife switch robust enough to handle the amps ) on the negative circuit with the knife in closed position, use vehicle like you normally do activating all electrical components, place the amp meter in parallel with the shunt. Make certain you have turned off electrical loads, like lights, then open the knife switch and watch amps.

Fuzzy memory here, I remember some amp meters (Fluke?) are resistant to excessive amps so be careful to not burn up your meter.

Anticipate you may see 3 or 4 amps (guess on my part) and condition could be intermittent. So a number of attempts may need to be made. Once identified pull the fuse circuits for components until draw goes away.

Hope helps.

life is a ride
1,540 Posts
I'm assuming that the negative battery cable is disconnected and the amp readings .01/.02 amps are the actual load measurements with everything turned off.
That load is likely the security system and should not drain the battery.
One possible issue could be the airride compressor trying to maintain pressure when the car is sitting.
The power antenna could energizing to power up/down.
Two things. Some load is draining the battery or you have a bad connection that is acting like a dead battery.
Also, when you say the battery is dead, how does it act.
And make sure the battery is fully charged before parking the car. Slow charge for 24 hours.
The charging system could be at fault. You may be parking the car with a dead battery.
The quick way to find the problem is AutoZombe. A diagnostic load test is performed on the entire system.


Car? Truck? Who Cares
2,485 Posts
I'm getting the same thing
Different alternators----new batteries----------Alternators----cs130 first and currently a cs130d
.028 draw is what I measured a few months ago when this happened.

Car will set sometimes for over a month and be just fine
This last episode it only sat for a week-----checked the battery------1.2 volts

(Pause while I go out and do some checking)

Charged battery 2 days ago to 12.6v
Just checked it again and it is at 11.7

Now I have a .28 draw
Disconnect sense/lamp lead from alternator-----still have .28 draw

Did a bit more checking and could hear a relay clicking.

Disconnect Vintage Air AC harness-----still at .28

Seems a ground wire came loose from the horns (or cheapazz horns failed)
AND----my horn button was stuck

Turns out the horn relay has been activated for I don't know how long.

Now----with everything plugged back in, I'm down to a .024 draw.

Well---still have a couple of vacation days to get that horn ironed out I guess.

So-----I guess a good thing to be checking for when when testing a draw, would be to listen
for any relays turning on.

I do seem to recall my horn not working one day----but I never expected the horn button to stick at the same time.
Damn reproduction parts!!!!

(shaking my head now)
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