Hi all,

Yesterday an ongoing overcharging problem got worse and I may be buying one of the 10 alternators that Kragens sells for my 63 225 automatic. Can anyone recommend a good one?

Here's the story just in case anyone can help figure out what the heck is wrong.

About a year ago my 7 year battery died in only 2.5 years. When Kragens gave me another one, I installed a new electromechanical VR since at high rpms my battery was reading about 17 volts with the old VR. The new one was only slightly better with the battery reading about 15 volts. A mechanic friend said the alternator was OK and got no better results with an electronic VR. So, I decided to live with my new battery and new electromechanical VR and buy replacement batteries every few years.

Yesterday, at 5 mph after a mid-day restart there was an odd sound and partial loss of power for a couple of seconds. Then everything was normal, but the dash ammeter was pegged all the way over to the right at 10 mph -- presumably indicating that my battery was being cooked. After a nervous 20 mile drive with headlights through rush hour (actually hoping traffic would frequently stop so the battery could discharge), my voltmeter read 12.8 volts with the engine off, but 16, 17, 18 and climbing at about 1000 rpms.

Today Kragens checked my charging system: battery OK under load, alternator probably OK and, of course, too many volts. Next, I'll bring in my alternator for a bench test which may indicate a bad diode.

All the connections seem OK and a jumper wire from the VR mounting bolt to the engine block didn't help. So, that's about where I'm at.

Thanks for reading this saga and thanks in advance for any suggestions on what to try next.

Zweistein

Those external regulators can be very touchy. It sounds like the alternator is receiving a signal for max charge. You should be able to determine whether this is being caused by your regulator or bad wiring.

Disconnect the regulator, preferably with the vehicle not running, and then start it. If it still overcharges you know it must be either wiring or alternator.

If it does stop overcharging with the voltage regulator disconnected, I would try to find a local electrical shop which can bench test your regulator. I like to test parts before I replace them.

My bet is that there's a wiring problem of some kind. This will require either someone more familiar with the specific setup on your vehicle or a competent shop. If you were in Long Beach, Ca I'd be happy to try to help. I worked in an electrical shop for awhile. In the meantime I'll look at mine. I'm not sure how similar it will be though... It's a 74.

My best guess is that by this, you mean the regulator is improperly full-fielding the alternator, i.e., the regulator isn't regulating. The only section of wiring that could cause this problem on a car using the '60-'69 "single field" charging system, because this system is regulated on the field feed side, is the wire running from the ignition switch to the regulator's "IGN" terminal. If voltage at this terminal is lower than actual line voltage, the regulator will perceive it as low line voltage and will send maximum available voltage to the alternator field, which will result in overcharging as described. It's possible the problem is with the ignition switch itself, or upstream of the ignition switch, but in that case other symptoms will be present (poor engine running and poor function of all electrical accessories live only when the ignition is switched on).
More hassle than it's worth, and very difficult these days to find anyone with the equipment and knowledge to test the regulator correctly. In point of fact, it is very likely that the regulator itself is at fault. Quick test is to turn on the ignition and use a voltmeter to check the voltage at the regulator's "IGN" terminal relative to a good ground (battery negative), then check the voltage across the battery itself. If there's a significant difference, repair the wiring. If not, replace the regulator. The electronic regulators available for the early system vary in quality and durability; I prefer the NAPA Echlin VR-1001 or Standard-BlueStreak VR-128.
Not the same at all; cars after '70 and trucks after '71 use a "dual field" alternator regulated on the ground side by a 2-pin electronic regulator. This later system can be retrofitted to earlier cars without much difficulty if desired, though the availability of good electronic regulators for the early cars presents an easier option.

To the original poster: The alternators (and starters, carburetors, brake master cylinders...) available as "remanufactured" parts from places like Kragen are junk. They tend to work poorly, fail early and often...despite the fancy "lifetime guarantee" they often come with.

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Too many people who were born on third base actually believe they've hit a triple.

Thanks for the points Dan. It's easy for me to recommend a shop to test regulators because I used to work at one. Evidently everyone is not so fortunate.

Don't forget to double check that your regulator is well grounded; often sheet metal screws don't ground as well as one would expect.

Also, an old trick for troubleshooting that may help is to place an old headlight in series with the field winding - it can serve both as a good current limiter and as an indicator.