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-   -   Generator Charging (https://www.fordbarn.com/forum/showthread.php?t=288946)

duffy 10-20-2020 10:11 AM

Generator Charging
 

When my '31 slant windshield is at idle the Ammeter is at zero. When I raise engine speed it goes to 10 and even 20 amps charging. When I move center brush up or down idle amps do not change, reads zero. Is my gauge bad? Could i have wires reversed on brushes? Gen motors when wires jumped.

31Tudor 10-20-2020 10:35 AM

Re: Generator Charging
 

You mention "idle amps". At idle, the generator cut out has opened and broken the contact, so you do not get any charging showing at idle. You would adjust your charging rate at a higher RPM, when the cut out closes again, moving the brush as you mentioned.

Kurt in NJ 10-20-2020 11:34 AM

Re: Generator Charging
 

If you were to read the instruction manual you would see that the car should not show a charge at idle or with the headlights on

Patrick L. 10-20-2020 12:05 PM

Re: Generator Charging
 

You failed to mention the fast idle charging rate after adjusting the third brush. Set it to a few amps if you drive mostly during the day, a little higher for at night. It really shouldn't be set for more than 10 amps.

duffy 10-20-2020 01:37 PM

Re: Generator Charging
 

Good info. Thank you. Will try again at fast idle.

duffy 10-20-2020 05:59 PM

Re: Generator Charging
 

OK, I increased the idle and set charging rate to around 8 amps. However, if I speed up engine the meter climbs and can go as high as 20 amps. Is this normal?

Patrick L. 10-20-2020 07:01 PM

Re: Generator Charging
 

No, its not normal. When I say fast idle I mean around in the 1000-1500 RPM range.
The charge rate should not go that high.

Curt phillips 10-20-2020 08:26 PM

Re: Generator Charging
 

Where should the needle be at normal driving speed with the lights on?

J Franklin 10-20-2020 09:02 PM

Re: Generator Charging
 

At or below 0

bobbader 10-20-2020 10:51 PM

Re: Generator Charging
 

Duffy, Sounds like you may be getting confused about how to set the third brush and you might need to start over. A good rule of thumb is to determine a starting point from which to adjust the brush in either direction. I always start by looking into the open slots in the rear of the generator and setting the third brush so that it looks to be equally distant in between the two other brushes. After doing so, get in the car, start it, and fully advance the spark lever. At idle, the ammeter may read zero or maybe about 2 amps at the most. Do not be concerned by this. Now, rev up the engine with the accelerator pedal. The ammeter should really go no higher than about 8 amps with the engine revved up. If it is higher or lower than that, now you have a starting point from which to move the third brush, in small increments, in either direction ............ toward the engine side of the generator for less charge .............. toward the fender side of the generator for more charge. Remember ........... SMALL INCREMENTS .............. until you get it to where it puts out no more than 8 amps with the engine revved up. If at any time during the adjustments you see a major spike in the charging rate, it might be time for closer inspection and repair of the generator itself. It may take several attempts to get the adjustment correct. Be patient. But, start with a reference point you can always go back and start over should you get flustered or frustrated. Good Luck, Bob Bader

Pat/Ohio 10-21-2020 08:02 AM

Re: Generator Charging
 

Quote:

Originally Posted by duffy (Post 1943550)
OK, I increased the idle and set charging rate to around 8 amps. However, if I speed up engine the meter climbs and can go as high as 20 amps. Is this normal?

Duffy, I believe there might be a little confusion here. Increase the idle with your foot on the accelerator not adjusting the idle speed at the carb. When you increase your revs (with your foot or by pulling on the carb. linkage), your amps shouldn't register over 8 amps. It is common to register at 0 or a little below when idling. You shouldn't register 8 amps when idling.

Pat

Purdy Swoft 10-21-2020 10:12 AM

Re: Generator Charging
 

I use the Fun Projects voltage regulator . I adjust the third brush for a ten amp maximum charge . The voltage regulator controls the amount of charge up to that point . The regulator takes the place of the cut out and prevents the generator from overcharging the battery and boiling the acid . Before installing the voltage regulator I would turn on the head lamps to reduce the charge rate when I would smell the acid boiling .

Big hammer 10-21-2020 06:00 PM

Re: Generator Charging
 

Duffy.......what shape is your battery in, water level, terminals ?

Gene F 10-21-2020 07:40 PM

Re: Generator Charging
 

If ya drive your car daily 0 is good. For us occasional drivers 1 amp with the lights off seems to be the sweet spot. Of course I do have a hand crank though...

Patrick L. 10-22-2020 10:35 AM

Re: Generator Charging
 

If you can't set the output low enough [ 2-4 amps lights off at fast idle/ slow cruise speed] then I'd recommend checking voltage output. These generators can produce 20+ volts if there is a poor connection/ground somewhere. Or, there can also be a generator problem.

Purdy Swoft 10-22-2020 11:01 AM

Re: Generator Charging
 

If the fields are connected backwards , the generator will still charge but moving the third adjustable brush will have no effect on the charging rate .

Badpuppy 10-23-2020 10:37 AM

Re: Generator Charging
 

1931 should have the coil connected directly to the generator at the firewall so the ammeter reads only battery current. The ammeter will read 0 until the cutout closes, after which you should expect >6 amps to replenish the battery after starting but should drop to 1 amp or so after a minute or two. A weak (shorted cell) battery won't charge to full voltage and will keep drawing a higher current and heat up. You may need a new battery.

Patrick L. 10-23-2020 02:14 PM

Re: Generator Charging
 

Charge rate shouldn't change with an original cut-out. If a regulator is installed then it will change.

Badpuppy 10-24-2020 09:41 AM

Re: Generator Charging
 

Quote:

Originally Posted by Patrick L. (Post 1944467)
Charge rate shouldn't change with an original cut-out. If a regulator is installed then it will change.

? -
Charge rate (current) varies with voltage, which varies with generator rpm.
Regulator limits voltage to a given level.


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