Having issues with my charging system since I installed a new rebuilt generator. My old generator was charging at 14.4 volts under load. I installed a new rebuilt chrome generator in place of my old one and now my amp gauge pegs under load at 16.6 volts. I thought maybe I screwed up my regulator when hooking up the new generator so I replaced that as well. Redid the wiring between the two as well. Still seeing 16.+ volts. What was cause that to happen? Could it be that something is amiss with the gauge maybe not grounded or something? This has me wondering what is going on. I was going to check the voltage at the battery under load but I need another set of hands for that. Tomorrow ill hook up the old generator to see if I get the same issue. I did polarize each regulator every time I hooked a new one up? Any ideas? Fryguy
Bought it from Master starter and alternator Here on the hamb. F terminal on gen is hooked to field terminal on regulator. A Terminal on gen is hooked to amp terminal on regulator. Battery terminal on regulator is going to the battery. Hooked ground wire from gen to side of the regulator. Tested the ground with voltmeter and I get 12.7 volts when car isn't running
How is the battery ? Your volt reg may be" reading " it needs to charge ... Coulld be a bad ground on the battery or engine
Test the running voltage at the battery terminals, with a known accurate voltmeter. Bring it up to 1500 to 1800 rpms to see what you get. If it really is 16+ at the battery, then adjust the regulator.
Had the same problem recently with a new (rebuilt) generator and new regulator. After confirming proper grounding and system wired correctly as well as polarizing the generator, I returned the regulator to the parts store and asked for another. A few days later, I got another regulator. I installed it. The generator now charges at 14.5 volts. Just right. The problem was not me or the generator. It was a faulty regulator. Maybe the same situation for you.
Ok, it maybe leaning towards a ground issue As I have swapped out 3 Voltage regulators and get the the same issue. Before I swapped generators, the system was charging at 14.4 volts. Something happened to the ground. Right now I have a ground running from the top screw of the GM generator directly to the voltage regulator. With the key in the off position I put the positive end of the voltmeter to the battery terminal on the regulator and put the negative rod of the voltmeter to the side screw on the regulator and I get 12.7 volts. Running at idle I get 12.8, running at 2000rpm I get 14.4, running at 3000 I get 16.7 volts.
Mechanical voltage regulator adjustments Erratic operation of the regulator, indicated by erratic movement of the voltmeter pointer during a voltage limiter test, may be caused by dirty or pitted regulator contacts. Vehicle ammeter pointer waver at certain critical engine speeds and electrical loads, is normal. Use a very fine abrasive paper such as silicon carbide, 400 grade, to clean the field relay and the voltage limiter contacts. Wear off the sharp edges of the abrasive by rubbing it against another piece of abrasive paper. Fold the abrasive paper over and pull the paper through the contacts to clean them. Keep all oil or grease from contacting the points. Do not use compressed air to clean the regulator. When adjusting the gap spacing use only hospital-clean feeler gauges. Gap VOLTAGE LIMITER The difference between the upper stage and lower stage regulation (0.3 V), is determined by the voltage limiter contact and core gaps. Make the gap adjustment with the regulator removed from the car. Bend the lower contact bracket to obtain a 0.017-0.022 inch gap at the lower contacts with the upper contacts closed. Maintain the contacts in alignment. Adjust the core gap with the upper contacts closed. Loosen the center lockscrew 1/4 turn. Use a screwdriver blade in the adjustment slot under the lockscrew. Adjust the core gap for a 0.049-0.056 inch clearance between the armature and the core at the edge of the core closest to the contact points. Tighten the lockscrew and recheck the core gap. FIELD RELAY Place a 0.010-0.018 inch feeler gauge on top of the coil core closest to the contact points. Hold the armature down on the gauge. Do not push down on the contact spring arm. Bend the contact post arm until the bottom contact just touches the upper contact. FINAL ADJUSTMENT Final adjustment of the regulator must be made with the regulator at normal operating temperature. The field relay closing voltage is adjusted by bending the relay frame. To increase the closing voltage, bend the armature frame down. To decrease the closing voltage, bend the frame up. The voltage limiter is adjusted by bending the voltage limiter spring arm. To increase the voltage setting, bend the adjusting arm downward. To decrease the voltage setting, bend the adjusting arm upward. Before setting the voltage and before making a final voltage test, the alternator speed must be reduced to zero and the ignition switch opened momentarily, to cycle the regulator.
Thanks Ron, is that still apply to the new voltage regulators, just bought an Echlin VR25. I have had conflicting threads, one saying voltage regulators should not be adjusted and others says they should be adjusted.
some replacement regs will have a riveted on cover ... your unit ? go back to napa and"you" look in the "book" in the back it will list all regs the are preset when they come with a riveted cover ... it is possible to find another with other settings looking this way in the "book" if possible ask the "manager" for some of these sets of catologs ... or offer to buy em they are a great" tool" a "aged" echlin numbered guide is best say from 1975-1985 and handy when you find n.o.s. parts in the boxes with no idea what they fit the cross reference is a very handy "tool"
Thanks Paper dog. Finally got some time to spend on this today. Switched out the new rebuilt chrome generator and put on my old rebuilt generator and everything is fine. Charging at 12.5 volts at idle and 14.4 under load. What exactly is going on with the new rebuilt generator? Is it possible it was rebuilt at a higher voltage output range? Thus I would need to find a different voltage regulator as well to handle the higher output generator?
When high voltage is constantly present and the charging rate is consistently high proceed as follows: 1. Connect voltmeter to regualtor "A" terminal and ground. 2. Run engine at idling speed. 3. Disconnect the field wire from regulator "F" terminal. If voltage reading drops it is advisable to install a new voltage regulator. If voltage does not drop the trouble is in the generator or the wiring. This was in the instructions I had for a P&D regulator. My regulator was acting the same as yours. It was ******* the volt gauge in the car and it turned out it was either a bad regulator or it needed adjusting. And this happened after I had the generator rebuilt. I was able to google the generator serial number and find out what year and model car it came out of and than was able to buy a matching regulator for that generator. It works fine now.
Brandon, I am thinking I probably have to buy a regulator that matches the output of the generator. I hook it up and it pegs the voltage meter. I connect up my old generator and it charges a constant 14.4 under load. Fryguy
Had the same over voltage problem on my '57. An armature or field pole insulator had failed. Can't remember which. Do a quick continuity check from each pole to the housing. Maybe someone you know has a Motors manual from the 60's. Those things are great for troubleshooting problems like this. They cover adjusments of the regulator too.
Did they have any suggestions? It appears that the generator is the problem here. Maybe it needs a different regulator to go with it but they should be able to tell you something.
Talked to Danny at Master Starter. He thinks its probably a ground issue. Since the generator is chrome its probably causing insulation issues. Tried the ground a few different ways but nothing has brought the voltage down. I swapped back to old generator for now.
Got the word from the generator shop. Word is that the field coils were bad and they ended up burning up the armature. This caused the generator to jump the field terminal any cause the runaway charging issue. Thats just one of those issues we run into when running these old parts they eventually do go bad. Looks like the generator needs a rebuild with new field coils and an armature. Fryguy
I am kinda between a rock and a hard place. The place I had the generator rebuilt and chromed told me it was perfect when it left his shop. The Generator shop that I dropped the genny off at when It was experiencing problems told me that the internals were all original inside and that the fields coils were bad. Paul
When the chrome guy dis ***embled the the barrel, he hurt the field coils. Not unususl when dealing with very old cloth w****d coils of copper. But he should have addressed this when he reasembled and tightned the shoe bolts. The full fielding of the generator causes the output to not be regulated and the generator, needing the regulator to control the field current, melted the armature. Generators are dumb and need the regulator. Blame this on the chrome guy not being a generator mechanic. Can you still buy new field coils and armatures? Are are you stuck with old used replacement parts? Frank
Frank, thanks for the input, that makes sense. I am just trying to get to the bottom of this now. I paid a gentleman to rebuild and chrome a GM generator. When I received the completed it was charging at over 16 volts, so i took it to a local shop to have it checked out and thats when I was told that the fields coils were bad and that burned out the armature. I was told by the rebuilder that I probably hooked up the generator wrong so that was the problem. The thing is I was running a plain GM generator before the chrome one. After I took the chrome generator off I put my old generator back on and everything is charging back to normal. I think I can still buy new field coils and armatures as that is what I ***umed I was buying when I paid to have it rebuilt.
Paul Back in time when rebuilding was common, it was done on the workbench, one unit at a time. Not like today when batches are done in a factory like setting. So even in the 60-70's when I worked at this stuff. One at a time. I reused every part that was serviceable. Field barrels were rarely disturbed, if the coils ohm'ed and ground tested OK and were not physicaly looking deteriorated they would be left in the barrel. sometimes I would take the fields out to put insulating shims under them if they were loose on the shoes. And then paint them with "red insulating enamel" . Armatures were checked for open and ground. If they looked su****ious they were tested on the growler. All got the comutators turned and mica undercut. Every generator got new brushes. The last step was to motorize the generator on the bench. Just to play with it and make ozone. Sometimes adjusting the brush plate for "timing". When I was doing this the labor was $7 for starters and $12 for generators. Plus parts. Regulators were all different prices, depending on how much out they were from fat fingered guys bending everything in sight. But almost never any replacement parts in a reg. So, anyway, when a generator is rebuilt on the bench, like your guys are doing, only the defective stuff gets replaced. The chromer should have caught the bad field coils after he put it back together and put in another set, or let you know they are no good and let you make the decision. Or reinsulated them before shorting them if they looked bad when he took them out. BAD judgement on his part. Frank
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