Author Topic: Battery Drain Problem  (Read 1579 times)

TX-302

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Battery Drain Problem
« on: June 22, 2012, 01:34:12 AM »
I'm having a battery drain issue and was wondering if there were any older strings on troubleshooting this particular problem?

Situation:
The the battery runs down after a two day sit. The alternator seems to charge after the initial jump indicating 14.7 volts across the battery terminals and then levels off at 12.7 volts. With the engine off - If I leave the battery (+) cable disconnected the charge stays or if I disconnect the Voltage regulator the charge also remains but if I reconnect them I lose the charge. I also noticed when I connect the (+) terminal in the dark there is a slight spark which may be the drain....or is that normal???

I've even tried disconnecting the fuse circuits one at a time to try to isolate the problem but no success.

Any suggestions would much appreciated! (The car is a 69 Z with a stock ignition system and orignal wiring that seems to be visually in VG condition)

Thanks!
Steve
69 Z

william

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Re: Battery Drain Problem
« Reply #1 on: June 22, 2012, 02:12:31 AM »
There was a tech service bulletin on the dome light bezel. The chrome plating created a current drain through the mounting screws. The fix was to scrape the plating off under the screws.

TX-302

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Re: Battery Drain Problem
« Reply #2 on: June 22, 2012, 03:25:36 AM »
Thanks....I'll give a try.
 Are the screws accessible after removing the lens?
Steve
69 Z

Charley

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Re: Battery Drain Problem
« Reply #3 on: June 22, 2012, 04:14:42 AM »
Get a little pigtail socket with a small bulb in it and put it in between the neg cable and the battery. It will light up if there is a draw. Pull fuses etc till the light goes out. That will narrow down the search. If the voltage regulator is the only thing that makes the light go out, try changing it.

TX-302

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Re: Battery Drain Problem
« Reply #4 on: July 01, 2012, 03:09:54 PM »
Thanks ....what is the correct amp rating for the 69 voltage regulator?
Steve
69 Z

mickeystoys69RSSS

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Re: Battery Drain Problem
« Reply #5 on: July 01, 2012, 03:17:20 PM »
Get a little pigtail socket with a small bulb in it and put it in between the neg cable and the battery. It will light up if there is a draw. Pull fuses etc till the light goes out. That will narrow down the search. If the voltage regulator is the only thing that makes the light go out, try changing it.

Charley you beat me to it. I learned this trick when I had an old 72 Chevy pickup. I did not know anything about electrical or wiring at the time and this process has help me narrow down electrical drains on every old car or truck I have had since.

JohnZ

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Re: Battery Drain Problem
« Reply #6 on: July 01, 2012, 06:48:36 PM »
Thanks ....what is the correct amp rating for the 69 voltage regulator?

The same 515 regulator was used for all applications, regardless of alternator output.
'69 Z/28
Fathom Green
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