1926 Generator problems

Another weekend and some more challenges with the buick...

Recently my distributor decided to give up the ghost (the pot metal shattered) and I had to take the generator off the car to clean out the remains of the shaft. It appears that I've disturbed something in the generator as now when I reconnect the battery I'm showing 10a drain with the ignition switched off. A continuity test shows that the windings still appear to be good, so I suspect that some insulation has come off some of the internal wiring but that's just a guess so any suggestion would be great?

Is there any special technique to removing the casing from it? I tried briefly but it didn't seem to want to separate easily

Did you check the cut-out relay? If the cut-out relay contacts were closed for some reason with the engine stopped, the condition you describe would exist.

Did you check the cut-out relay? If the cut-out relay contacts were closed for some reason with the engine stopped, the condition you describe would exist.

seems like the relay is opening and closing fine at 6V - are there some tests I should try with my multimeter?

This link may help with trouble shooting the cut-out.

Generator cutout relay - AACA Forums - Antique Automobile Club of ...

ok, had the regulator around the wrong way so now it doesn't just drain... however it's not charging either :/ as the previous thread mentioned my digital multimeter goes up and down crazily when connected to the side closest to the engine and shows a constant 6.1v on the other.

What's next on the check list

I've narrowed it down to a problem with the generator - I replaced the brushes and still not seeing anything more than 0.5v, so I'm at a bit of a loss as to what to check next - any ideas?

On a side note, the shop manual tells you that it should all come apart and to "remove the gear" which does not seem to come off on mine either (spins fine) but even with a puller refuses to budge.

hidden_hunter, I basically had the same result from the generator on my '26. It would only indicate 1 volt, turned free in the bearings and had plenty of brush material left. I contacted Jason at Advanced Electrical Rebuilders in Michigan. He has the equipment and know how to completely rebuild these generators as well as set the third brush for proper charge. I just shipped my generator to their facility. Apparently the gear requires a hydraulic press for removal. Perhaps you could locate a similar specialist in Australia.

hidden_hunter, I basically had the same result from the generator on my '26. It would only indicate 1 volt, turned free in the bearings and had plenty of brush material left. I contacted Jason at Advanced Electrical Rebuilders in Michigan. He has the equipment and know how to completely rebuild these generators as well as set the third brush for proper charge. I just shipped my generator to their facility. Apparently the gear requires a hydraulic press for removal. Perhaps you could locate a similar specialist in Australia.

I was hoping to try and avoid that but if it needs to go to a specialist (any Aussies know of anyone good?) :\ It's a bit disappointing because it was charging fine until I took it off the car to replace the distributor that had fused on it, I've tried fresh brushes and replaced the wire to the regulator thats insulator was falling off and I'm not getting anything from it. It runs as a motor if connected to a power supply (not super fast, probably 400RPM tops) and if spun with an electric drill geared to 800RPM it's not seeing more than a volt come out of it.

I took some pictures of the brushes just in case I messed up something obvious

Have you checked the switch on the dash,you can messure it to 6volt on the cut out relay, but do you get enough ampere thru the switch.Maybe the fingers inside the switch has been burned,in that case you can messure 6 volt on the relay, but you dot get any amperes thru the switch when loaded it.Amperemeter in serie can tell you that.

Leif in Sweden

Have you checked the switch on the dash,you can messure it to 6volt on the cut out relay, but do you get enough ampere thru the switch.Maybe the fingers inside the switch has been burned,in that case you can messure 6 volt on the relay, but you dot get any amperes thru the switch when loaded it.Amperemeter in serie can tell you that.

Leif in Sweden

I've got the whole unit out of the car at the moment to eliminate as many possibilities, so measuring directly off the generators output with my analogue multimeter

That would be disappointing in as much as the generator was working fine until it was removed for distributor repair. The brush enclosure and commutator slots appear clean.

My generator was in much worse shape, lots of carbon dust mixed with grease. In addition, the commutator was out of round. Was definitely ready for a rebuild. I am by no means a generator expert. However, there must be a simple test one could make with your multimeter to troubleshoot the windings and determine the problem. Hopefully, others will chime in who have troubleshooting experience with these generators.

from what you have told us it sounds like the gen is ok if it motors when you put power on it im guessing you are putting batt volt straight onto gen and by passing cut out I would try to turn the unit faster the speed of your drill may be to slow

from what you have told us it sounds like the gen is ok if it motors when you put power on it im guessing you are putting batt volt straight onto gen and by passing cut out I would try to turn the unit faster the speed of your drill may be to slow

what sort of speed would I need to get it to any sort of meaningful voltage output? I've got it up to about 1v when powering using a corded drill, spins ok but not fast if I use an old car battery charger as a power source

When looking at the transmission gears you can use the same speed as on the engine normaly runs to get the ampmeter on + charge around 200-1000 rpm.

Leif in Sweden

I'm giving up before I break anything on it and sending it off to a specialist locally, will update this thread once I know what the problem was so others in a similar circumstance will have an idea where to look

Update, specialist has taken a look at it - basically the commuter is heavily worn with the brushes are making very poor contact and essentially skipping over the surface. New brushes on the way from the states which should be here in a couple of days with any luck so they can commence rebuilding it

On a side note, I believe it has the original or at least very old brushes in it as well - they've actually got Delco stamped on the brush itself

Thanks for the update. How did he get the gear off?

Thanks for the update. How did he get the gear off?

hasn't had to yet