The Stovebolt Site Forums The Shop Area The Electrical Bay generator output

The first nighttime drive in the 58 Spartan revealed a problem: the generator doesn't seem to keep up. The lights, which include headlights (not on high beam) as well as cab marker lights and of course taillites, dash lights, etc. were all on....got home last night and the battery was very low and needed to be charged before it would start again. The generator is an NOS factory rebuilt unit and not original to the truck...it seems to keep up fine normally, but with lights, is apparently insufficient. I do notice that, even in daylight driving, the ammeter shows little to no charge at lower RPMs, but I thought this was normal for generators. Dumb question: would a slightly smaller pulley increase the output? Also, maybe I'm looking at a short somewhere ??....as in, when the lights are on, an extra drain is occurring? Your expertise/personal experiences with generators would be appreciated....thanks!

Buy an alternator today before you go on a 8 page study of ancient electrical philosophy and endless tests of all those wires, the voltage regulator, the generator, battery chemistry, idle speed, polarizing, near death if you get an alternator, belt tension, brushes, contacts, coils, relays.............
One thing you won't hear is anything negative about a alternator. Nothing. Silence.
Delco 10si, $50, to your door in three days, two wires, throw everything else in the dumpster. done. ALL trouble gone.

3,,,2,,,1,,

PM sent- - - -call me.
Jerry

Thanks Bartamos, for your advice; and Jerry for your reach out (I will contact you). Bartamos, I agree that from a totally practical POV, an alternator would be the best solution and I enjoyed your way of putting it! However, I would like to sort the generator issue a bit. I've run many 6 and 12 volt generators in vintage cars, trucks and tractors over the years and have had good luck with them, excepting the occasional 'fry', when the unit completely burns out. My experience, although I'm certainly no expert, tells me that there is something beyond the usual 'headlight drain' going on in this case.

I

I have a 1958 Chevy C60 Viking and I get along great with my generator. I don't drive it much at night but when I turn my headlights on bright and speed the engine up a little the amps gauge still shows it is showing enough charge to be to the plus side.

It is normal to have to rev the engine some above idle for the generator to charge. As far as installing a smaller pulley on the generator, you should be able to rev the engine up farther to see how a smaller pulley would work better. I doubt if it would help that much.

There is also the matter of the voltage regulator, which may or may not be up to par.

I'm not trying to steer you away from an alternator if that is the best way to go. Just sayin.

I was going to suggest voltage regulator also. Sometimes pulling the cover off and giving all the points a good cleaning is all it takes. Note I said "sometimes"!

If you enjoy the interesting aspects of the generator system and like the originality, by all means carry on. I like to fix things so they don't break again as best I can. A brushless, integral regulator, integrated circuit, better output at low speeds alternator is fun not to worry about. Jerry is your man for troubleshooting. I was pulling his chain and he went on me. Good move Ex-lax. I'm going to check fold.

you can also change all your marker lights and tail lights to LED if you want to keep your generator. That will at least cut back some of the load on it. Regulator can be messed with, etc... My 58 ran fine with the generator, till it died 2 hours away from home on a Saturday night. I made it most of the way home on just the battery! Pulled off the freeway (had to turn off the headlights to keep it running) and drove to the nearest auto parts store and bought a new battery to get me home. I installed an alternator the next day!

Beware of Echo and Nemesis, and stay away from reflecting pools.
Jerry

Always make sure the belt is tight, a loose belt will give the symptoms you are having.

Ed

Thanks everybody, and I also enjoy the tit-for-tat debate on alternator vs. generator! There is a possibility of a belt issue, which I looked into today. The belt I've had on for a short time was 'cheap' in cost and maybe cheap in composition, and seems to have caused some 'slicks' on the pulleys. I put an old Gates belt on as found in my parts bin, and adjusted the tension, but first cleaned up/sanded the pulleys. Still, when I put the headlites on, the ammeter dips well below center at idle, not that I totally trust its accuracy. Like a couple of you said, maybe the regulator? The generator is 'new'....that is, it's an NOS unit rebuilt by General Motors, I believe rated at 30 - 35A.

jaycoop I,d listen to bartimous have learned to double belt the alternator so it will carry all the loads you mentioned at idle ! then you can go back in and finish your coffee while she "warms-up" !!!!! LOL !

That is normal for the charging to go to discharge with the headlights on at idle. A lot depends on the idle speed & size of the gen. pulley.
Put a volt meter across the bat or bat term of the regulator. It should run up to about 14 volts when you rev up the engine.