VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt 1927 chevrolet generator output question

I am working on a 1927 chev touring car. My question is what should the generator output be? I have just got it running after working through many fuel and ignition issues. Now that it is running, the ammeter is indicating 20 amps charge. I borrowed a fluke clamp on dc ammeter and it reads around 18 amps. The service manual says anything over 12 is not good and requires a third brush adjustment. Anyone have any advice on this?

You move the third brush to reduce the current. Others in here will know for sure, but I think 18 amps will melt it. Systems like this had no voltage regulator, so how much current was needed depended on the driver. Too much and the voltage will just run away and cook the battery once it gets full, burn out bulbs, etc.

The idea is for the battery to be charged just full when the owner gets home and shuts the car off for the day.

Even 12 amps sounds like too much to me, but I have no 1927, so can't say for sure.

Thanks for the reply. I just took the generator end cap off and found the adjustment for the third brush. I am going the moved it and retest it.

I was able to adjust the brush to get an output of around 12 amps. Thats as far as i could adjust it. Still seems a little high.

The maximum output position of the 3rd brush on a DELCO-REMY 943-B generator,is no closer the 2 1/2 commutator segments from the + main brush,which is the brush closest to the LH mudguard.The maximum cold output is 16 amperes,8.0 volts @ 1,600rpms(engine revs),or about 25mph.The maximum hot output is 12amperes,7.7 volts @ 1,800 engine rpms,again about 25mph.To reduce the output,loosen the clamp screw slightly and move the 3rd brush arm towards the engine,but not too far,as the 3rd brush arm may come into contact with the top through bolt.
If you still can't get the output down any lower than 12amps,then you may have to look at taking the cutout off the generator,checking the air gaps & point gap,then upon re-installation,you should check the cut-in voltage of the cutout(the voltage needed to close the points on the cutout),which should close somewhere between 7.0 volts - 7.5 volts.A closing voltage any lower than 7.0 volts will cause undercharging and a closing voltage higher than 7.5 volts will cause over-charging.

Thanks for the reply. I will check the cut off unit on the generator as my next step. I did check the voltage when it was charging at 18 amps and it read 6.8 volts. But dud not check it after i moved the brush. I will report back my findings. I won't be able to work on this for a few days unfortunately.