1950s 59 Gen problems again...

[Cadillac Jack 82]

So the replacement generator I have on the car has been fine...until my idiot butt left the lights on at work for 10 hours with my cover on.  I got a jump and she ran fine but died half way home.  Got another jump and she died again pulling into my carport.  I charged the battery at Autozone thinking that was it.  She started fine but then popped her gen light.  If I rev it without a load she'll get rid of her gen light...but it comes back on again at idle.  What gives?

[Jeff Rosansky CLC #28373]

I would first start with polarizing the generator.

[Cadillac Jack 82]

Polarized the gen right after I installed the charged battery

[Dave Shepherd]

Get a volt meter on it see what you have  at 1500 rpm. If low, ground the field terminal on the gen momentarily,  should go to 15v.

[Cadillac Jack 82]

Sadly I tested the gen and its not doing anything.  What is causing these darn things to keep frying out?  I cant imagine a dead battery caused this...

[Dave Shepherd]

Ok, you had no gen output after grounding the field  terminal? if so the generator is the problem.

[Cadillac Jack 82]

Is it bad rebuilds or what?  I did everything by the book and this is the second Gen to fry out...

[Daryl Chesterman]

Sadly I tested the gen and its not doing anything.  What is causing these darn things to keep frying out?  I cant imagine a dead battery caused this...

A completely dead battery will cause this.  What happens is that the generator is supplying maximum amperage for too long of a time and usually causes the problem you had.  I had a 57 Chevy that I had left the headlights on after driving in the fog.  I had someone give me a jump and it started up fine, gen light was off, and I drove it about 10 miles before the gen light came on.  I was able to get to the nearest town, and the Chevrolet dealer had a rebuilt (this was in 1970) that was installed.  The mechanic said that there was solder slung around the inside of the generator case on the commutator end that was caused by the generator operating at peak amperage for too long.  A generator is not designed to operate at peak amperage but for a short period of time—one of the short-comings of a generator.

Daryl Chesterman

[D. Mailan]

Yes, I will parrot what Daryl said. A dead, or even a poor battery places a huge strain on the charging system. The voltage regulator, is forced to charge your battery rather than supplying energy to your electronics, thus causing the dummy light to come on. That may be the problem on your car.
Derick

[Cadillac Jack 82]

The good news is the first gen that failed was repaired by the seller and is in route.  Guess I'll have to rebuild this one.  Thanks everyone.  Sucks I cant just pop by Napa and get a new one lol.

[bcroe]

Can be fustrating.  After many rounds (over many
miles) I bolted a 63 alternator bracket on my
62 and installed a 76 internally regulated alt,
threw away the mechanical reg box.  Only takes
3 wires.  Bruce Roe

[Cadillac Jack 82]

If anyone has an extra clean, functional 35 amp generator please let me know as I'd like to buy it.  The first one is still in transit back to the rebuilder after the USPS screwed up delivery and the second one is dead.  I can get the second one rebuilt locally, but I'd like to have a working one ASAP to get my car back to her garage.

[Jon S]

I would first start with polarizing the generator.

No need to polarize a 1959 generator

[Cadillac Jack 82]

Welp just found out the first one that went bad is rebuilt and it'll be here Friday.  She should HOPEFULLY be ready to go by Friday afternoon.

[Cadillac Jack 82]

First rebuilt gen is back in the car.  The seller replaced the armature due to the other one failing.  I plugged everything in however shes barely charging at 14 volts.  The voltage regulator is a Standard 35 amp one from O'Reilly.  Everything is new on the charging circuit.  Any idea why she's not charging at 14.5-14.7 volts? 

[Dave Shepherd]

That can vary based on many  factors, underhood temps,  load on the battery, regulator settings. Again, to see if a good max output is available, momentarily  ground the field wire.

[Cadillac Jack 82]

I'll try that.  I also ordered the correct NOS delco remy voltage regulator.  While I'm sure these Standard types are fine I don't trust modern made components.