battery draining

[Daniel Grunwald]

I have a 67 big block and the starter wouldn't work one day after charging the battery fully. I had the starter rebuilt and then it happened again the next week. It wasn't a problem with the starter at all but the battery is draining if I leave it connected for a couple of days. It drains to completely dead. When I charge it and start the car it idles with the ammeter showing charging about halfway on the dash gauge. If I bring the RPM's up to around 2500 then the meter pegs at full charge. The voltage regulator looks fairly new and the points inside seem to be very clean and move freely. Any advice as to where to start looking? I'm not very good at troubleshooting electrics. Thanks, Daniel

[Dick W.]

Re: battery draining

Are you sure that the glove box lamp is cutting off when the door is closed. This a common item that will drain the battery

[Jon #40768]

Re: battery draining

I have a car that did that when the altinator had a bad diode.
Jon

[Wayne K.]

Re: battery draining

Daniel,

To expand on what Dick has suggested just because the light goes out doesn't mean that it isn't putting a draw on the battery. In my opinion that glove box light socket is a goofy setup. I had contact going on in the socket when the light was off that kept draining my battery. Check that circuit for a draw with the bulb out if you find that the light is going out when the door is closed.
Also have the battery tested. You might just have a bad battery.

Wayne

[John M.]

Re: battery draining

Had the same problem. Bad diode in alternator.

[Daniel Grunwald]

Re: battery draining

Thanks for the responses. I don't think it is something as small as a glovebox bulb because even with the battery fully charged the gauge on the dash is pegged beyond the max at anything above an idle. My thought is that something, (voltage regulator?), is calling for the generator to put out max charge when it really isn't needed and this may be the reason for the battery drain as well.
Daniel

[Dick W.]

Re: battery draining

You pretty much eliminated the diode when you said it was pegging the ampmeter. A faulty diode will limit you to about 10-15 amps max. An old trick when you do not have a lot of diagnostic equipment is to remove one fuse at a time. See if you get an arc. Remember the clock will arc only when it resets. Block your interior light switches. Slow, but the process of elimination will sometimes save you a trip to the shop.