The Stovebolt Site Forums The Shop Area The Electrical Bay 6v ammeter reading ?

All right guys, I've been having some issues, I have a 53 GMC 100 5 window with the 228 inline 6. As far as I know it's orignal I'm the 3rd owner , 2nd to have it on the road. The truck has a Delco Remy 1102793 generator well I had a melt down , lost the armature had it rebuilt , then had the voltage regulator melt down. So fried everything , had it rebuilt again, bought a ac Delco 45amp voltage regulator now I'm charging 6.8 ish volts I can watch the ammeter click on as I rev the truck up but it is only pulling 5ish amps according to the gauge. I'm not sure if this is correct or not? Before (for the last 7 years) it would read 25 to 30 amps on the gauge can anyone tell me what I should be pulling here. I understand it's not a voltmeter. But even running the heater and lights it will pull it down to 0 maybe a little under. Is it just not drawing the battery down enough to excite the voltage regulator I'm not sure and I'm getting tired of burning up that generator

A dash ammeter is about as accurate as sticking your finger out the window for a speedometer. It's just a glorified charge/no charge indicator. Does the needle sit in the middle of its range with the engine off, and does it deflect in the (-) direction when things like high beam headlights and the heater blower are operated with the engine not running? How was the regulator adjusted when it was replaced? There are three mandatory adjustments that need to be made- - - -closing voltage, current regulator setting, and voltage regulator setting. Just buying a regulator and bolting it on has about a 10% chance of working properly. The shop that rebuilt your generator should have been able to match the output of the generator to the voltage regulator, if they know anything at all about the old charging systems. That's the way I've done it since the early 1960's.

With a fully charged battery, you should see 7.5 volts at the battery posts with the engine at 1500 RPM or so. Your 6.8 volts is WAY low unless you have a seriously discharged battery.
Jerry

Jerry, THANK you, for over 50 years I have wondered about 6 volt amp gauges. I always put a meter on the generator and then looked at the dash meter and by looking at the needle position at various positions at different RPM's to get an idea. Back when we bought new regulators what was the trick to get it to work properly? Was it putting the base on the negative battery poll and just wiping a wire on the positive mark on new regulator? Or is that now done at the factory? Dad taught me that the trick on a new a new regulator had to be polarized or it would ruin the generator or not work at all. I remember doing this procedure in the day but have forgotten how. Ed

Regulators do not have to be polarized. Generators do, by connecting a jumper wire momentarily from the BAT to ARM terminals after all the connections are made. In fact, making any sort of connection before the regulator is bolted to the body and properly grounded is risky business. The only thing any regulator does is control the output of the source of charging current, whether it's a DC generator, an alternator, or even the single phase "stator" that I'm currently having issues with on my Harley bike. That one uses a bunch of coils under a spinning permanent magnet on the engine crankshaft, and a solid state rectifier/regulator unit to turn the AC current it produces into regulated DC to keep the battery charged.

The only surefire way to check a new regulator is with an accurate volt/ampere tester like the Snap-On unit that I use, and remove the cover and make the adjustments I described by adjusting the spring tension on the points if anything is out of specification. Just bolting a regulator on without adjusting it is roughly equivalent to drawing to an inside straight in a poker game- - - -the chance of success on that is 32:1!
Jerry

Those old generators are about 30 amps rating. If you have a 45 amp regulator you are putting too much load on the generator & throwing the solder off the armature windings.
The regulator current limiter section could be adjusted to match the gen. but it takes some special equipment & knowhow. The shop that does your gen. should be able to
adjust it correctly.
George

Thank you Jerry, now that I have your and George's attention; I put a long Delco generator on my 54-3100 rather than the short one ( had to put longer bracket on). I have had no problems keeping two deep charge batteries under the floor fully charged in series. This way my Lexus/Acura whatever a/c can work directly on 12V. Do you think it is putting too much on the bigger generator? Everything that is six volt still is on six volt (gauges,lights, generator, starter etc.). Ed

Cadillac, Olds 98, and a few big Pontiacs ran a heavy duty generator with a 45 amp capacity. The best way to identify that one is to look at the rear end frame- - - -it it's got a ball bearing there instead of a bushing it's the heavy duty model. George is correct about the current regulator needing to be adjusted to match the generator capacity. Most of the short housing Chevy 12 volt units were somewhere in the 25-30 amp range. The stepped-frame long ones were in the 35-45 amp category, with maybe a few heavy duty big truck generators going 50+ amps. Those are usually also bigger in diameter, however.

Thanks, It does have a ball bearing in the back plate, it has been on my 54-3100 for 44 years. About 36 years ago I used a hand crank armature lathe and replaced the brushes. It has about 6500 miles on it since so I better check to see how its doing.

Back in the dark ages when those generators were on everything, it was not uncommon for one to last 30K miles or more with only routine maintenance- - - -topping off the oil cups on both ends when the engine oil was changed. At 6500 miles, the brushes will barely have any wear at all.
Jerry

I just rebuilt the generator and went to the manual for the regulator adjustment instructions. I opened up my regulator to discover it resembled the manual photos only vaguely, leaving me to believe someone did some swapping without much thinking. Anyway, in doing some further research on what to look for in the way of a new regulator, I came across this helpful thread that has me a bit confused. The manual appears to say that the base generator is 45 amps. Mine has a bushing in the back and is presumably then the base model, but both George and Hotrod seem to be saying it's 30 amps. I don't want to end up buying a voltage regulator not suited to my generator, advice on what to be shopping for would be much appreciated, I'm not seeing any 30 amp regulators so far.

Lots of reading on old Delco generators and regulators here: http://www.navioneer.org/riprelay/The%20Navion%20Files/navion.htm

Looks like your generator is 45 amps.

Regulators for positive ground vehicles are different than regulators for negative ground vehicles. Voltage and polarity should be stamped on the base.
see page 8 of this document: http://www.navioneer.org/riprelay/The%20Navion%20Files/Delco_Remy_Generator_Regulators.pdf