Midyear electrical discharge problem
My 1964 stock 327/300 has never had any electrical issues but I have one now. Over the winter I didn't use a triclke charger and the battery was of course too weak to start. Charged it, started fine. Now I can't keep a charge. I think I have a big hint in that the amp gauge upon start is slightly above zero, indicating a charge. Then, within 2-3 seconds, the gauge flicks over to below zero, indicating a discharge. It's very abrupt and always the same few second elapsed time. Any ideas where to start looking would be most appreciated. /David
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Re: Midyear electrical discharge problem
Dave,
disconnect the clock and use a volt meter on the battery terminals to see if you have a draw. to do this first place the probes on the + and - terminals with the cables hooked up. Then remove the negative cable and check again. if the volts increase when the negative is removed there is a draw somewhere. If not then your battery simply won't hold a charge anymore. Thats the simplest place to start. (I always say don't look for something that might not be there to start with)
Rich -
Re: Midyear electrical discharge problem
Dave, let's also see if the reg and alt are working. With engine running around 1500 rpm, you should see at least 13.9v on the batt terminals measured with a vom. If you don't have that voltage, suspect the alt. If it's higher than 15v, you got a bad reg.
If above checks out OK, may be time for a Optima battery.Comment
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Re: Midyear electrical discharge problem
Just to throw another wrinkle in the mix, sort of as a confession, I once had a similar problem and all but rebuilt everything trying to rectify it. Turned out I too had the car laid up for the winter and this occured in the first few weeks of spring and I had forgotten how the old ignition switches worked. I was turning it all the way CCW to the Accessory position and draining my battery dead. I got fooled by the key being removable in that position, just like with my street car.
Stu FoxComment
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Re: Midyear electrical discharge problem
Thanks for the tips guys. I have a volt meter, the kind used for high voltage as well but it doesn't seem to be working properly even with the change of the AA battery. It is a cheap one so I think I'll invest in a proper automtove style when the stores open tomorrow. I do have the stick type that does show the battery is charged (when car off) and also charging properly with the car running.
I'll check tomorrow to see if some type of draw is occurring. Re the ignition switch, yes I had the exact same problem on my other '64 when the switch shifted slightly and said off when it was on accessory. I small adjustment and that issue was fixed.
Thanks again. Will post after I get a proper meter.Comment
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Re: Midyear electrical discharge problem
Dave, by your last post, you answered the question, Time for a Optima. Not cheap at all around 150.00, but WELL worth the piece of mind. Bill.Comment
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Re: Midyear electrical discharge problem
I actually thought the battery was not that old but now believe it's about 7-8+ years old. Time for a new one I suppose. I'm still a bit surprised the amp gauge is showing a discharge if the charging system is working.Comment
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Re: Midyear electrical discharge problem
Dave, the alt is charging the battery,BUT the battery is not, cannot accept the charge. That's why you're showing a discharge on the ammeter (which is really a voltmeter). Buy the battery and charge it several times over the winter. Optima 34-78 is the one you want. Bill.Comment
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Re: Midyear electrical discharge problem
Dave,
I think what you are seeing is that the battery is unable to fully hold a charge and slowly drains off from the last time it was run, so when you start the engine it takes a few seconds for it to register that the battery needs a boost. And it only drained a little because you are not letting it sit for any great length of time to fully discharge. Thats why you have a few seconds of charging when it starts up.
Just to be sure yhou should like you said still check for a draw when you get a good meeter.
RichComment
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Re: Midyear electrical discharge problem
Thanks again guys. I will go ahead and buy the new battery and check the draw as well. The battery is getting too old for my liking and if it's not the problem, it will be soon.Comment
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Re: Midyear electrical discharge problem
The ammeter would still show a charge, unless by some strange quirk the battery or something else, shorts out and pulls off more current than the alternator is capable of delivering. A normally weak or bad battery would not cause a discharge indication on the meter with the engine running.
You need a new battery. Its way past its useful life. But, there is something else going on if that gauge drops under zero with the engine running above idle.Comment
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Re: Midyear electrical discharge problem
I don't know if this is a maintenance free battery but if it isn't you might want to check your battery acid levels. Too low also prevents your battery from charging properly...
regards,
Rob.Rob.
NCRS Dutch Chapter Founder & Board Member
NCRS Software Developer
C1, C2 and C3 Registry DeveloperComment
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Re: Midyear electrical discharge problem
Finally got around to buying a new battery. I went with the Optima red top as recommended by previous posters. With a voltmeter, the battery shows 12.9 with the car off, 14.0 at idle, and 14.5 at 2K rpm. The ammeter is still showing a discharge though. The gauge needle is slightly below zero when the car is off, goes to zero upon start-up, and then after a second or two moves to negative by about an eighth of an inch. Am I to assume the gauge is whacked out or do I have other issues? All comments gretaly appreciated.Comment
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Re: Midyear electrical discharge problem
Dave, glad you got the red top. I'm a bit concerned about the battery resting voltage (12.9). It should be around 13.6 or so. Suspect this is due to battery sitting on shelf, and it's not fully charged. This should go away with driving the car.
Your other voltage are right on, so I think the gage is toast. Monitor the resting voltage and if does not improve, let us know. Bill.Comment
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Re: Midyear electrical discharge problem
Dave, giving more thought to your problem. Don't swap the ammeter just yet, let the battery get to full charge and see how it acts then. BillComment
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