29 da generator question

[RobV]

Well, i finally took it out at night and other than the fact I realized there are NO dash lights (how do you guys deal with that) it was pretty fun. One thing I noticed is that my generator usually is showing 15 amps charge when Im driving during the day and it drops to 0 when I am stopped at a light. At night when I turned on the headlamps the amperage dropped to 0 or a little below. That made me a little nervous. If I turned on the cowl lamps then I was at a continuous 3 amp discharge. More nervous. When I came to a stop at a light it was showing 15 amps discharge. [img]<>/eek.gif[/img]

Is that normal in your experience or do I need to rebuild the generator and set the regulator?

[1930]

You should have a dash light, all of them had the sigle bulb that illuminated bahind the gauges. I can provide a pict. if you need it.
As far as I know they always show discharge when idling, I have never personally driven my car at night but if you look in your manual you will see that there is a third brush adjustment ( Which I know nothing about ) and at the same time you can look at the condition of your brushes. There are guys here that I am sure will give you more info on electrical than you may want to know.

[RobV]

Could you please post a pic. The instruction book only says that the instrument panel light is controlled by a switch at the base of the panel but the front compartment diagram doesn't show where the switch or light should be. Thanks!

[keiser31]

The dash light switch on my 1931 is along the lower lip of the dash.

[RobV]

Thanks,

I think I found the light bracket mounted on the back of the oil gauge. The previous owner primered the backs of the gauges and covered the little windows, but thankfully the primer is coming off with a little rubbing compound. Now I just need to find the right style switch and a lamp holder.

[DodgeKCL]

Fifteen amps is too much to have showing on your ammeter during the day. This will create too high of a voltage on your battery and it will try to 'climb' up to that high voltage and that will result in the battery getting HOT after it reaches it's normal terminal voltage of about 7.5 volts and you will have to keep putting water in your battery to keep it from drying out and the plates warping. Whew! Got that?
As the other gentleman said you have to adjust the 3rd brush for max. current on a discharged battery. If you don't have a VOM or equivalent then turn on your lights for 5 minutes and then start the car and adjust the 3rd brush for a max. of about 15 amps., everything off. You'll find the 3rd brush by removing the cover band on the rear of the generator. You'll find one of the 3 brushes is on an eccentric and the eccentric is held tight by a slot screw on the rear plate of the generator. If you loosen this screw you will find the 3rd brush slides back and forth. When you go to adjust it while the engine is running, use a wooden stick or the plastic/wood handle of screwdriver to keep from shorting anything out. Adjust the hand throttle for an idle just above normal idle and push the 3rd brush back and forth while someone (wife?)watches the ammeter on the dash. When it stabilizes at 15 amps have her switch off and you tighten the screw.
Next-drive the car a bit with no lights on and wait to see where the ammeter stabilizes. It should stop at about 5 amps. After a good drive switch on the headlights and the ammeter MUST stay in the positive. If it doesn't go back and tweak the 3rd brush just a touch until it does. You cannot drive a car with the ammeter in the negative. The engine will eventually start to buck and fart from poor ignition let alone your lights will be 'brown'.
It is normal for the ammeter to drop to the negative side when you pull up to a stop. This is caused by the generator coming off line (cut out) and all the current coming from the battery. The moment you move away the ammeter HAS to return to the + side for all the above reasons.
For the longest battery life you should have the lowest amount of current showing on the ammeter's + side under all driving conditions,night and day. I get 10 to 12 years out of a $45 six volt battery. I adjust for about 2 to 3 amps. This keeps the battery happy,the headlights bright and the ignition strong.
At the end of the day the car's overall voltage will read about 7.5 volts running down the road,with or without headlights. If it never reaches that point after all the above adjustments and driving, you have a duff battery. If a d.c. generator will put out 15 amps then it is not going to starve the system for overall voltage because a 6 volt generator will actually put out 20 odd volts. I have found that only thing that determines the overall voltage on pre-voltage regulator cars is the battery. In fact it is the ONLY thing I've found to set the health of the system.

[1930]

Thats a great explanation on Gen. adjustment, Rob that is right about the bulb bracket being attached to the back of ammeter, I know you prob. dont need this now but here is a pict. and if you look closely you will see the toggle switch lower right corner attached to lip of dash and trace the wire you will see the bulb.bracket assy. Interesting that you will see the exact same holes under the lip of your dash on opposite side for right hand drive cars. I may have one or two of these switches, havent looked lately

[keiser31]

That's like the dash light switch on my '31s.

[Joe Cozza]

1930
Ah, to be young.I have all I could to get under my dash in my "31",let along take such a nice clear picture.

[1930]

Well it gave me a chance to not only lay down on my back but to sneak in a nap before my wife got home.

[RobV]

Thanks for all the great help on this. All of the guage 'windows' for the light cleaned up, except for the speedo, which had old packing tape with the strings in it for a window.

The switch looks like just a basic toggle. Is that about right? Does the lampholder that goes in the bracket 'snap' into the holder or does it bolt in? Early Harley's had a lamp holder with little 'fingers' around the lamp that snapped into holes like the one in the bracket.

I'm going to try to adjust the generator tomorrow. Wish me luck. LOL

[1930]

The switch is just a basic toggle, the first time I saw one I just about threw it out because I thought it was much too modern and there was no way it was original. The bulb holder is held into place on the bracket by two little guide pins that correspond with holder/bracket. The bracket itself is held onto back of gauge with two little slotted screws and lockwashers. Hope this helps

[RobV]

DodgeKCL,
Thanks for the info. I think I got it all. I don't understand though why 15 amps during the day with everything off now is too much, yet you said I should set the generator for 15 amps slightly above idle with everything off. How does setting the amperage at 15 amp slightly above idle get me to seeing 5 amps driving down the road? Does the charge rate vary with battery charge? If so, then perhaps my new battery is faulty and it is requiring the generator to supply too much. I keep the battery on a tender whenever it is not being used [img]<>/eek.gif[/img]

I have a question about the ammeter itself. The previous owner disconnected the original ammeter for whatever reason and it is running on a 'new' ammeter like you would buy from a local parts store. Being as our cars are a positive ground while the gauge was made for a negative ground car, and given the workings of an ammeter, isn't it possible that the meter could be reading backward if improperly installed?