When I inquired a short time ago about the length of time it took for my car to start charging. Usually after a couple of miles, it would begin to charge to the predetermined third brush setting. As time has passed, it has taken longer and longer for the ammeter to swing into the charge position. Today I squirted some Napa electrical CRC onto the armature and third brush through the inspection sight. I then took the car out, drove it, and could not get it to charge after any length of time. I returned home, removed the top from the regulator, cleaned the battery hookup, sanded points lightly, and tried again. I am 90 percent sure this generator was done over just a short time ago. Can anyone recommend a step by step diagnostic procedure fit for a mechanical simpleton, to determine the problem?
Hi Tony, can you remove the cover over the brushes on the generator? If so, inspect each brush, make sure that each brush slides freely in it’s rectangular guide, and that the spring actually IS exerting pressure on the brush to keep it in contact with the commutator.
Since spraying some contact cleaner on the brushes seems to have stopped the generatrr from charging, I’m thinking that the commutator is oil covered and the cleaner did not clean, but allowed oil to cover the surface and stop the brushes from making electrical contact.
I’d use a screwdriver, or similar item to push against the end of each brush while the engine is running, often this will push the brush firmly into contact with the commutator and it will start charging.
If the commutator is black, covered with oil and carbon, I’ve used a strip of wet/dry sandpaper, 220 grit usually or what ever i can find, and lift up a brush, slide the sandpaper under the brush then rotate the generator, pushing on the brush to apply pressure to the sandpaper to clean the commutator.
Hope one of the above will get your generator ‘genning’
Here is a site with more info than you may need, but it has a lot of good info.
Here is one on regulators
Will take out generator in the next couple of days and look inside. Thank you all for your feedback.
Hi Tony, just a thought I had today. You mentioned that the generator appeared to have been rebuilt in the not too-distant past. It might be possible that the generator has such a good paint job on it, that it is not grounded to the engine.
Take a jumper wire, and make a new, solid ground between the case of the generator and the engine block. The problem may as simple as the mounting of the generator is not providing a good ground for the case. If I remember correctly, there are straps that clamp the generator to a round cradle on the side of the engine block. If the paint is thick enough, and there is no other way that the generator case is grounded, this might just be the problem.. Worth a try.
I removed the generator from the 36 earlier last week (1 mashed thumb, some profanity). An accomplished wrench came on Friday, totally disassembled the generator, polished the commutator, snapped the brushes (I then took the plate assembly outside and cleaned it with CRC). Put back on car: no charge. Replaced the regulator (I have a new extra)no charge. Put on my spare which I had gone through years ago, and it took right off charging, with just a slight amount of acceleration upon starting the car.
I sent the generator back to Rochester, to the people who have been doing my generators for some time. It is interesting that the non-functioning generator took miles of driving, becoming progressively worse over the years, until it would not charge at all. It will be interesting to see what the problem is.
Incidentally, the late P-A generators and starters will fit in a priority mail large flat rate box (around $17). A bargain, the generator w/regulator weighs 28lbs. Stay tuned.
Thanks for the update Tony-looking forward to the rest of the story.
Golden Alternator and Starter from Rochester, N.Y. called yesterday to tell me that the generator was repaired. He tested everything inside, turned the commutator, revarnished things inside, etc. The cause of failure was the deteriorated brushes. He found exact replicas of the brushes in Texas for around $95 (all three). The third brush contacts were detached or all but detached from the leads. Total cost for repair, around $150. He noted that all brushes were in a deteriorated condition. Bob Sands whose work in the steel mills involved electric motor maintenance, mentions that cleaning solution should never be sprayed on brushes, as their failure will be imminent. An interesting aside is that the generator I had on the shelf, that is in the ’36 now, begins to charge immediately. Bill at the repair shop says that the rebuilt unit also begins charging at low RPM. Perhaps the slow startup for charging prior to the total failure on my unit, and some other people’s (Ed Minnie) is an indication of poor brush connections, and possible future failure.