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Old 11-06-2019, 05:58 PM   #1
Cape Codder
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Default AMP Meter Reading

I recently drove my A on a short trip that I decided to turn my lights on. I have an original generator and a six volt electrical system. I also have a generator cutout which I believe has a diode inside. To me it seems to act as a voltage regulator but I am unsure that is a fact. During this short trip I noticed that the AMP Meter at the very best would only registrar 2 AMP's DISCHARGE.

My question is can I move the third Generator Brush so that it will read 0 AMP"s or is this not advisable?
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Old 11-06-2019, 06:07 PM   #2
Bob C
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Default Re: AMP Meter Reading

How many amps is it putting out with the lights off??
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Old 11-06-2019, 06:08 PM   #3
Kurt in NJ
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Default Re: AMP Meter Reading

If you were to read the owners instruction book you would see that a discharge with headlights on is normal
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Old 11-06-2019, 06:41 PM   #4
rotorwrench
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Default Re: AMP Meter Reading

A diode, such as is used by the folks that make the generator safety device type units in a cut out like can, will only allow current flow as it comes from the generator. It won't regulate the output at all. The fun Projects set up or other similar fabricated units are the only regulator in a cut out shaped can that I am aware of. When the battery is charged back up with these type units, the meter will go to minimal charge which takes a good amount of load off the generator.

The first thing I look for is whether the car has an original ammeter or not. I don't trust the reproduction units much. If it is the original type meter then it will show the output that is flowing. If the reading is low then it could be due to condition of the generator. A person would then have to adjust the 3rd brush so as to increase the output to specs and then keep an eye on it for a while. It also wouldn't be a bad idea to do an inspection of the wiring connections at the battery cables and between the generator and the ammeter or at least at the connection to the terminal box. I've seen the modern reproduction terminal boxes get damaged if the terminal gets loose & creates too much heat. The check is not to much work and will give more piece of mind.

Last edited by rotorwrench; 11-06-2019 at 06:48 PM.
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Old 11-06-2019, 08:39 PM   #5
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Default Re: AMP Meter Reading

Thanks to all for your responses!

Bob C - When the lights are off it usually runs at zero. It usually goes to 6 - 8 amps charging and stays there for just a couple of minutes after starting and then returns to zero.

Kurt in NJ - I understand that it will go to discharge but thought it should come back up to normal operating at zero. Is that not the purpose of the third brush?

rotorwrench - Would you know how to tell the difference in what type of protect I have without taking it apart? I don't have any info on it. Thanks for other suggestions which I will look into.
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Old 11-06-2019, 10:39 PM   #6
sethkestenbaum
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Default Re: AMP Meter Reading

It shouldn't "return to 0" unless you are doing something that would cause this to happen. I once got confused when I was reading a lower output than I expected but then realized I was stepping on the brake (the brake light uses amperage).

For normal day driving, I attempt to set the third brush on my powerhouse generator to give +2 amps with the car engine "at speed" and parking lights "on". This configuration lets me decide if I want to drain the battery (by having my regular lights on), charge the battery quickly (with no lights), or charge the battery slowly (with the parking lights on). The goal is to have a nice charge on the battery and not let it drain too much or overcharge. I've found this to be a great base line and then I will change the charge rate by adjusting the third brush if I know that I am going to drive at night or be in a parade and use the horn a lot.

If you haven't set the brush before, it is actually easy. loosen the third brush screw a little (if it is a powerhouse) and then start the car and have it on a high idle and turn on your parking lights. Look at the ammeter. Tap the third brushholder up or down using a chop stick (so you don't get a shock) to increase or decrease the output. Look at the ammeter. Repeat until you have the charge rate you like.

I hope this helps.
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Old 11-07-2019, 07:52 AM   #7
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Default Re: AMP Meter Reading

Sounds like you have a fun projects regulator on it. Your ammeter center may not be truly zero amps. With engine shut off look for zero on the gauge. Here is how mine is set up: turn lights on low beam with engine at maybe 1200 RPM, adjust 3rd brush to just a titch on the + side of zero. At high beam it will discharge at about 2 amps or less, at low beam it will maintain.
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Old 11-07-2019, 08:57 AM   #8
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Default Re: AMP Meter Reading

Like everyone else has said, a slight discharge with the lights on is nothing to worry about. I will say, based on your response #3 it does sound like you have a regulator. A normal cutout should register a constant current at a constant RPM.

If it is the Fun Projects regulator I don't think you'll have an issue bumping the charge rate up with the lights on.
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Old 11-07-2019, 09:26 AM   #9
Kurt in NJ
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Default Re: AMP Meter Reading

The 3rd brush controls the maximum amps, in a stock system--and with just a diode cutout , the idea is it was adjusted for your use, if you just take long trips with no night driving it would be set for lower amps, if only short trips --and night use it should be higher, if your battery becomes discharges thecharge rate is too low, if the battery uses a lot of water the charge rate is too high

it seems that you have a fun projects regulator most likely, there are limits on the max charge rate that it will handle(15 amps)without burning up, and it is less than the generator can produce

years ago when I was using 50cp bulbs I would crank the brush to 18 amps to make them bright
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Old 11-07-2019, 10:12 AM   #10
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Default Re: AMP Meter Reading

I've heard the fun projects cans are marked for voltage on the bottom of the can since they make them in three different voltages. It would have to be removed from the generator to check. I'm not sure if the lid comes off or not on the diode types. The original cut outs are spot welded on the edges several places around the bottom edge of the can where it joins the mount plate. They can be disassembled but a person has to locate the little welded spots & carefully grind them to free the can.
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Old 11-07-2019, 10:40 AM   #11
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Default Re: AMP Meter Reading

erase

Last edited by Benson; 11-07-2019 at 11:05 AM.
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Old 11-07-2019, 10:39 PM   #12
Mike V. Florida
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Default Re: AMP Meter Reading

Quote:
Originally Posted by Cape Codder View Post
I recently drove my A on a short trip that I decided to turn my lights on. I have an original generator and a six volt electrical system. I also have a generator cutout which I believe has a diode inside. To me it seems to act as a voltage regulator but I am unsure that is a fact. During this short trip I noticed that the AMP Meter at the very best would only registrar 2 AMP's DISCHARGE.

My question is can I move the third Generator Brush so that it will read 0 AMP"s or is this not advisable?

Sounds like your system is working normally. The minus 2 amps are coming from the battery to assist the generator. I have driven for more than an hour with my ammeter reading the same as yours. When I got home I put the car on a trickle charger.


With that said if you are going to drive for a couple of hours in the dark then move the third brush until the meter reads 0 with the car running and then you can drive anytime with the lights always on.


One more thing, the diode is nothing more then a switch and as such does not regulate anything.
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Last edited by Mike V. Florida; 11-07-2019 at 10:51 PM.
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Old 11-08-2019, 09:39 AM   #13
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Default Re: AMP Meter Reading

A diode is like a one way check valve in a hydraulic system. It allows the current to pass in one direction only. They are generally made in a way that you can tell which direction it should be installed in the circuit. They can go south on you too. When they do, they can open the circuit completely or allow some current to flow both ways. An alternator has a whole bridge of them mounted inside for the same purpose as the cut out but it also has to bridge the current from AC to DC so that it will work in a motor vehicle.
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