Not charging sometimes
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Racer
Joined: Jan 2008
Posts: 299
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From: Surprise AZ
Not charging sometimes
Question about charging system on a 66. I put a volt meter across the battery and no charge, (car is running). Showing 12 volts, then it starts to move little by little 12,13 14 15 16 then pegs at 16. That's as far as my meter goes. Changed regulators same thing, checked wiring looks good, voltage wear it suppose to be. Took alt. to auto zone said it was bad.Then took it to a rebuilt shop, said it was good. Then sometimes it doesn't charge at all. Alt. is #'s match, rebuilt about 13 yr's ago. I only have about 800 miles on the motor in 13 yr's. Everything is like new. what's up thanks. 
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Le Mans Master
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Le Mans Master
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I wrote an article that explains the theory and testing of this charging system that should help you.
PM me.
Joe
Melting Slicks
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From: Wilton Ca.
I had the exact same issue. My money is on a bad regulator. If you're running a fairly new mechanical regulator my advice is to replace it with a VR-715 solid state unit. I had THREE new mechanical regulators give me problems (the new ones are junk junk junk, 3 X's for 3 bad ones 
) until I switched. Haven't had any problems since!
Almost any auto parts store will have them and they usually run around 15 to 20 bucks. The VR-715's come with a short, glued on plastic cover. To make it look stock simply pry off the cover, set the old cover over it, mark and drill the two mounting holes. Reinstall and then check your readings.
Gary
) until I switched. Haven't had any problems since!Almost any auto parts store will have them and they usually run around 15 to 20 bucks. The VR-715's come with a short, glued on plastic cover. To make it look stock simply pry off the cover, set the old cover over it, mark and drill the two mounting holes. Reinstall and then check your readings.
Gary
Last edited by Gary's '66; Mar 2, 2016 at 01:57 PM.
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I agree with the regulator being the possible problem but if you replaced it and got the same readings then I would suspect a bad ground at the regulator. As far as a shorted field I don't believe that could be your problem. If you want to check just remove the plug from the back of the alternator, then it is inside the alternator, if not then you will have do search further.
I wrote an article that explains the theory and testing of this charging system that should help you.
PM me.
Joe
I wrote an article that explains the theory and testing of this charging system that should help you.
PM me.
Joe
Joel, I've not written any articles so I'll defer to you. The only way an alternator can go to full output is to full field the rotor, which would as you agree above, be internal to the alternator given the test above. Please explain how that is not an internal short and if not what could cause it.
Last edited by dplotkin; Mar 2, 2016 at 09:01 PM.
Thread Starter
Racer
Joined: Jan 2008
Posts: 299
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From: Surprise AZ
I agree with the regulator being the possible problem but if you replaced it and got the same readings then I would suspect a bad ground at the regulator. As far as a shorted field I don't believe that could be your problem. If you want to check just remove the plug from the back of the alternator, if it is still overcharging then it is inside the alternator, if not then you will have do search further.
I wrote an article that explains the theory and testing of this charging system that should help you.
PM me.
Joe
I wrote an article that explains the theory and testing of this charging system that should help you.
PM me.
Joe
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Joel, I've not written any articles so I'll defer to you. The only way an alternator can go to full output is to full field the rotor, which would as you agree above, be internal to the alternator given the test above. Please explain how that is not an internal short and if not what could cause it.
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I agree. Couldn't one or more failed diodes allow an AC component to raise the voltage? I wonder what reading he would get with the DVM set to AC volts across the battery engine running.
Dan
Dan
Thread Starter
Racer
Joined: Jan 2008
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From: Surprise AZ
UPDATE, Took the cover off the regulator, and the black wire connected to the base and the other end is connected to nothing. Not sure where it goes. 1119519. Will a VR 715 replace my 1119519 for now? I have a 55a alternator.
Last edited by joescvette; Mar 4, 2016 at 05:26 PM.
Race Director
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From: Charlotte NC
The wire that is attached to your regulator housing is needing to be GROUNDED.....so if the wire is attached to the regulator...but the other end of the wire is going nowhere...attach it to a good metal ground point.
DUB
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Last edited by leif.anderson93; Mar 4, 2016 at 08:24 PM.
Thread Starter
Racer
Joined: Jan 2008
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From: Surprise AZ
Update
Thread Starter
Racer
Joined: Jan 2008
Posts: 299
Likes: 4
From: Surprise AZ