Battery Drain

[Jim (across the pond) Adamek]

I have a slight problem. With the key off I have a slight drain of the battery. Over a period of 2 days the battery will completely drain. If I disconnect the battery and reconnect a day later the car will start just fine so it is not the battery. I have no electronics on the old girl that could cause a drain of the battery. Truly old school wiring. How can I determine what is causing the drain of the battery? The voltage meter on the dash does not show any drain when the key is off.

[Dave Adams]

Alternator?

[Jim (across the pond) Adamek]

How can I tell if the alternator is causing the drain?

[Steve Kerswell]

Pull the cables off, then try it in the morning. If it starts OK, it's the alternator, I think :-)

[Jim (across the pond) Adamek]

OK, Thanks Steve. I'll give it a try.

[Jim (across the pond) Adamek]

Well It is the alternator that is causing the slow drain of the battery. Is this normal or do you think that there is something wrong with the alternator? If something is wrong is there a way to repair it?

[Big Vern]

Do you get a feint glow from the ign/gen warning light (you'll only see it in the dark) The alternator shouldn't cause the battery to drain. I can only think there maybe a fault with the diode pack.

[Jim (across the pond) Adamek]

No ign/gen warning light on the old girl also I do not believe that it has a diode pack. Now I did have a problem with the ground wire shorting out against the alternator about 6 months ago and I had to replace the bushing on the negative stud which melted down but the alternator has been working out just fine since then.

[Big Vern]

If its an alternator then it must have some sort of rectifier as its ac 3 phase and needs to convert to straight dc. Not having a warning light could be a problem as the ign/gen light usually switches the alternator so that it will start charging once rotating, without it will just discharge.

It sounds like you may have internal damage of some sort given the problem you had previously.

[Jim (across the pond) Adamek]

When I start the car I need to tap the gas pedal to get the alternator to start charging the system. The draining is probably an internal problem. I would to like replace it but pretty expensive. I will continue to use the disconnect battery disconnect switch for now.