Amp meter question again from the newbie????

DeBordEngineMan

DeBordEngineMan

Senior Member
Hey guys it's me again with a problem or a question, it's about the amp meter I thought mine was working right and a friend said that I have my wires wrong on back of meter but he also said it before I thought I had it hooked wrong before I changed it the way it is now? Really confused after that statement? In other words I have had my wires on both posts and each time he says they are hooked backward....only two ways to hook it up? OK this is what my meter reads....with car running at idle speed meter reads around to be 6 to 7 amps on charge side then I can turn on lights and it will go up to about 15 amps on charge side also when I blow horn the amp meter go's up or when any light is turned on the amp meter go's up accordingly, before I changed it the way that it is now car running at idle speed showed a discharge of about 6-7 amps and turn lights on or blow horn it would go to 15 amps discharge just vise versa from the way it reads now....SO NOW! he says that the car running should be around 10 amps at idle speed and when I turn on lights it should go back to zero or blow horn it should go back toward zero so now I am now totally confused? He is more than not to be right but I thought my amp meter was working right and generator was charging right but now I have no ideal which way is right I am new to the hobby and I try to listen to folks that know Model A's and try and learn from them but sometimes they are wrong to....But in this case I am now clueless? Any help out there? Hope I have not confused you to much???? because I am, Thanks Robert DeBord.
 
With the engine off turning on the lights (or other electrical item) should move the needle to -
With the engine idling on a generator system you should still have a - reading, when you speed up the engine the needle should move toward +

How far the needle goes to + depends on where the charging rate is set in your generator ( if your generator is stock), and what loads are on ---with the headlights on, and brake lights on you should expect to see - reading even when the generator is making max charge --and that is normal.
 
Sounds like you had it hooked up correctly the first time. Kurt laid it out pretty well: if the meter moves toward negative/discharge/left side when you turn on lights or horn, the meter is hooked up correctly.

If I understand correctly, it sounds like your problems began with a failure to show charge with the motor running. If that's the case with the motor revving fast, and the meter moves the right way (left) when lights are turned on, then it sounds like your generator or, more likely, the cutout are not working. The cutout is basically a switch that puts the generator into the circuit if it is spinning fast enough to make enough voltage to be helpful; otherwise, it cuts the generator out of the circuit to prevent the battery from draining backwards through it.

Steve
 
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Yep to what the boys said,but, you didn't mention whether you are using an alternator or a generator.. It sounds like you do have the ammeter wires on backwards right now.. The generator will not charge until the engine speed is raised above an idle[actually, an alternator won't either].. The generator output is controlled by the movable/adjustable third brush if the generator has not been modified..
 
Hey guys thanks for the input I am running a stock generator I guess, I have not had it checked or anything hoping it was charging correctly I thought I had it hooked up right the first time but my amp was showing a neg. charge when running and more neg. with lights,horn on so I guess that it was right the other way even though it still showed a neg. charge so to understand you Kirt without the car running if I turn anything on I will show a discharge correct? Then start my car and speed up the engine I should see the meter move to the charge side but it may still be on the discharge side of the meter right? then if I turn anything on I will see a discharge again and if I turn lights or anything off the amp meter should move back to the charge side but still could be on the discharge side of the meter is this correct? If it does not do this it means the generator or the cutout is bad correct? Can I bypass the cutout to see if the generator is putting out to see if it is a bad cutout or generator is bad itself? Would like to keep the generator if it is good but it may be easier to install a alternator. Thanks Robert DeBord
 
Hi Robert,
Your description leaves a lot of possible contradictions in my mind.
Please advise what, with engine off, happens when you put the lights or horn on. This will conclusively tell you if your accessorys are correctly hooked up.
The amp meter should go to DISCHARGE when the lights are turned on, and even further when you beep.

THEN, with lights off, start the car. The amp meter should shoot to CHARGE immediately.
Reactions after that can be a function of your cutout compensating for discharge.

FIRST advise us of what happens in the first tests I suggested.
This will be CONCLUSIVE and pretty much irrefutable.
 
Hi Robert,

First off, I must state the the comments and advice from those that have already posted are accurate and helpful.

In addition to the fellas on the Barn, good sources to turn to for help are the Andrews books, and other tried and true publications available from the vendors.

For the definitive answer to a wiring question like yours, as well as the lighting circuit, I found the wiring schematics to be invaluable. A simple fold-over chart, it clearly spells out, in detail, what goes where. It even helped me identify a puzzling error that the manufacturer of the light harness was building in to their assembly regarding bright and low beams. (They were happy to be informed of it and have corrected those on the shelf, as well as their ***'y jig.

Hope this helps,
Steve
 
DeBordEngineMan said:
Hey guys thanks for the input I am running a stock generator I guess, I have not had it checked or anything hoping it was charging correctly I thought I had it hooked up right the first time but my amp was showing a neg. charge when running and more neg. with lights,horn on so I guess that it was right the other way even though it still showed a neg. charge so to understand you Kirt without the car running if I turn anything on I will show a discharge correct? Then start my car and speed up the engine I should see the meter move to the charge side but it may still be on the discharge side of the meter right? then if I turn anything on I will see a discharge again and if I turn lights or anything off the amp meter should move back to the charge side but still could be on the discharge side of the meter is this correct? If it does not do this it means the generator or the cutout is bad correct? Can I bypass the cutout to see if the generator is putting out to see if it is a bad cutout or generator is bad itself? Would like to keep the generator if it is good but it may be easier to install a alternator. Thanks Robert DeBord
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Bob,

This is all basically correct with the possible exceptions of the parts about the ammeter not showing charge or being in the + range with the motor running. If the motor is running at a fast idle or greater, and the lights are not on, and the generator and cutout are working, and the wiring is right, the ammeter should register in the positive range. It takes a few amps to run the ignition system (points/coil/plugs) so there will be a small discharge at low idle. Unlike a voltage regulated system, even when the battery is fully charged, a generator/cutout arrangement will keep cramming more electrons through the circuit, ultimately overcharging/damaging the battery.

Do you have halogen headlights? If so, your generator might not be able to satisfy their current demand even if everything is set up correctly, which could produce the symptoms you describe.

If you are not obsessive about authenticity, there's a real good reason that the whole automotive world converted to alternators once good permanent magnet technology became available. If you have halogens, an alternator is pretty much essential. Otherwise, at the very least consider a diode replacement for you cutout's innards--it lets electrons only go one way and with no moving or sticking parts. Or, better yet, some slick true voltage regulators are available that can be tucked out of sight in the Model A generator or maybe in the cutout can. That's the way I would go if I didn't have modern headlights and didn't mind having only a pathetic horn while the lights are on. If you do the "3rd brush adjustment" to increase the output of your generator and stick with a cutout, you are at great risk of overcharging your battery and/or burning up the generator unless you drive with your headlights on all the time.

You can bypass the cutout with a wire jumper from the "input post" coming up out of the generator on the firewall side of the cutout to the "output post" coming out of the front (pulley end) of the cutout. If you do this, BE SURE to disconnect that jumper when the motor is turned off or you'll come back to a dead battery.

Did you try some serious tapping on the cutout with a big wrench. There are parts in there that can stick. If the contacts stick shut, the battery will go dead after you've stopped for a while--the cutout will be hot to the touch. If the contacts stick open, the system will never charge, which sounds more like your situation.

Steve
 
Hey everybody I changed the amp meter wires like they are suppose to go per Les Andrews book also keep in mind that this amp meter is a import so it is off a little, just a little under zero with nothing on, battery disconnect off, now 1. with car not running with lights off I can turn key only on and amp meter will show a very low discharge 2. with car not running with lights on will show a discharge of about 15 amps 3.With car running no lights on meter shows discharge of about 7 amps 4.With car running lights on shows discharge of 15 amps blow horn and discharges more amps turn lights off with car still running goes back to about 7 amps as before It never shows the amp meter on the charge side of the meter with the car at idle or at a higher speed. I have all my lights working and working as they should headlights hi and lo beams, horn, taillight,brake light, dash light I think that my problem is with the generator or cutout not working and is not showing a charge on the amp meter. Is that what it sound like to you all? Can you bypass the cutout some way to see if the generator is putting out a charge? I understand what the cutout is suppose to do but I think it is not working right. What do you all think? Thanks for all the feed back Robert DeBord.
 
DeBordEngineMan said:
... Can you bypass the cutout some way to see if the generator is putting out a charge? .. QUOTE]

Bob,

If you slog through my prior post, you will see how to bypass the cutout

Another test: If you have a multimeter, set it to DC volts and see if there is any voltage difference between the input post going from the generator into the cutout and any unpainted ground with the motor running at fast idle. Anything over 7.2 volts should be good enough, if the cutout is letting it through. There is very high probability that your cutout is bad.

Steve
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Hey Steve I am running stock headlights and I did hit on the cutout pretty hard, nothing happened the cutout does not get hot to the touch I have a new battery about 9 months old bought new when I bought the car has never been weak or went dead I would like to stay with the generator because I think that a alternator just looks out of place but for a daily driver which this is the alternator is the better choice. So will more than likely go with alternator if I get a 6 volt alternator will the amp meter hook to this or is there a special meter for the alternators that I will need to get? Thanks Robert.
 
DeBordEngineMan said:
... So will more than likely go with alternator if I get a 6 volt alternator will the amp meter hook to this or is there a special meter for the alternators that I will need to get? Thanks Robert.
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Bob,

I'm a big fan of alternators but in your case I think staying with the generator is the way to go. The looks matter to you and that's never going to change. Without halogens or other add-ons, the generator will suffice just fine IF you get a good voltage regulator on it. If you can't find one in a catalog, I urge you to start another thread entitled "good voltage regulator?" or some such asking for advice--it won't take long. I know there is one on the market that hides out of sight: I haven't used it but I have only heard good things about.

Also, this is serious stuff, worth involving a professional. Take your generator off and take it to an auto electric shop to be refurbished. Be sure and tell them "positive ground", which I assume is your case. I would (did) do the same with the starter, by the way.

The same ammeter would work fine with an alternator. They start out making AC current, but built in diodes convert it to DC--otherwise it couldn't charge the battery. If you do decide to go with an alternator, might as well go whole hog and go to 12 volts.



Steve
 
The ammeter does not care about the voltage, or if the car has an alternator, or generator.

I have a generator, and have halogen bulbs , I have my charge rate set to a + 1 amp charge with the lights on ( works out to about 13 amps)
 
You might try polarizing the generator. Touch a short jumper lead across the cut-out terminals, it only takes a nano-second.. See if that helps.. Generally this isn't needed unless the generator has been apart or has set around for a really long time, but, it could be worth a try.. If it doesn't work, then remove the cutout leads and fed power to the generator and see if it wants to motor, if you loosen the belt it should spin freely with power applied to it.. If it does motor then You've got yourself a defective cut-out.. Most cut-outs can be checked, cleaned and adjusted, the originals are best..
 
All the cut out does is shut the current off to the generator when the motor isn't turning it. That way it won't try to turn into an electric motor. When the gen starts genin it creates a magnetic field that pulls the points closed and allows the gen to put out some current. The modern ones are just a diode like an alternator has. It only allows current one way. On the back of the power house gens you can adjust the third brush to get more current but I would advise that you have a good amp meter set up to do this. The one in the car can be used but it is still kind of a guess on how much output your getting it up to. You definitely don't want to go too far. The later type gen is a little different than the powerhouse but it still works the same way.
 
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