Calling all charging system guru's!

moonshine runner

moonshine runner

Senior Member
Hey guys,

Awhile back I posted about my charging system dropping when the car idled but would pick up at higher RPM, or running down the road.

I got a lot of good replies, some that said that's normal for a 6 volt system, and just continued to drive the car.

I also kept thinking and studying on the charging system. I also own another antique car, which has the generator and regulator and it always maintains even voltage and does not drop at idle like my Ford.

Well, a few weeks ago I decided what the heck, I would replace the brushes in the generator and see if the headlights still dimmed at idle. Well, they did, and I drove the car to work yesterday morning and this time the needle on the ammeter was going just over into the discharge side so, I decided to buy and install a new regulator since I have no idea when it was replaced last.

I put the regulator on tonight when I got home from work and polarized it, then started the car. The voltage was stable but now the ammeter needle remains just on the discharge side.

So, the things I have not done was actually have the generator checked to see if it is charging. I have not load tested the 8 volt battery to see how healthy it is. It has been acting just slightly draggy but not bad.

So, any suggestions what you all would check at this point?

Thanks in advance!!

Kevin
 
I'd replace the 8v battery with a 6v Optima, then see where your ammeter stands. Being over voltage to begin with, your 6v regulator isn't calling for a charge. If your previous posting had revealed the 8v battery, I'm pretty sure you'd been advised to go with the 6v system at that time also.
 
Kahuna said:
The very first thing I would do is get rid of that 8 volt battery
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Amen. A stock regulator should only let the generator put out 7.2 volts which will not charge up an 8 volt battery. You need 20% higher voltage than the battery to charge it. That's 9.6 volts! Although you might be able to adjust your regulator to put out that many volts you'd be risking all of your other 6 volt things like the radio, coil, bulbs, etc.

Won't know whether you have any other problems until you do that. Might have saved the money on the regulator and put it toward a 6 volt battery.

If you want a battery that looks more authentic than the Optima you can get the NAPA 7244. It's the same dimensions as the original, has 640 CCA, and can even be "disguised" to look like the original like I did mine. ("disguise" kit $30.00 here: http://www.ebay.com/itm/330376684091...84.m1439.l2649)

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Thanks guys. I didn't mind replacing the regulator and the needle isn't jumping around like it was. I will replace the battery tomorrow and get a new 6 volt and see how it acts then.

I bought my car with the 8 volt battery in it.

Kevin
 
Kevin, I'm sure you will both solve some problems and reveal some previously hidden problems when you replace that battery. the important thing is that you're proceeding in the right direction, and will get it all together this way. Get back at us with an update and more questions.
 
Kevin, as a general rule a generator will not charge at engine idle speed of say 500 RPM. You have to increase the revs to maybe 1,000 RPM before a charge will show on your ammeter. Alternators will usually charge at idle speed depending on pulley size and some other factors. When that 8volt battery was fitted your original regulator voltage should have been adjusted higher to compensate and likewise the new reg would also need adjusting. Even after adjustment of reg the generator will still not charge at idle which is normal. You should not really mess with regulators unless you really understand how they work and what to adjust. There are at least 4 different adjustments/settings which have to be checked which are 1. cutout closing voltage and opening reverse current. 2. Current regulator max amps setting. 3. Voltage regulator settings. Find an "OLDER" auto electrician to do it for you. The young ones are not taught this old stuff these days. Possibly both regulators will work OK if you refit a 6 volt battery. I think the optima battery is about the best choice. I have had them last up to 14 years so far. Many emergency services use them as the standard fitment. See how you go. Regards, another Kevin.
 
Ok, so here's the update.

Today I bought a new 6 volt battery from the local NAPA store (the 7244) battery that Prof. Henry mentioned and installed it when I got home from work.

The ammeter is not showing in the discharge side now but rather in the charge side. The lights don't seen as bright as they were with the 8V battery but it doesn't seem to be discharging now and the needle don't move to discharge with the headlights on at idle.

So, I guess now I will get out my multi meter and do some voltage checks to see what's going on.

Kevin
 
moonshine runner said:
Ok, so here's the update.

Today I bought a new 6 volt battery from the local NAPA store (the 7244) battery that Prof. Henry mentioned and installed it when I got home from work.

The ammeter is not showing in the discharge side now but rather in the charge side. The lights don't seen as bright as they were with the 8V battery but it doesn't seem to be discharging now and the needle don't move to discharge with the headlights on at idle.

So, I guess now I will get out my multi meter and do some voltage checks to see what's going on.

Kevin
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Sounds like everything is right within normal specs to me so far. Lights will certainly be dimmer on the proper voltage but still bright enough and the bulbs will last longer. Here are the detailed specs if you want to check them:

RegulatorSpecs_zpsd16198e5.jpg
 
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Kevin, that's good news! As for your lights not being as bright, that's understandable and predictable. They won't burn out near as often now either! You will also notice the starter won't spin as fast, which will save the Bendix snd flywheel gear from damage.

Now here's what to check with your voltmeter: Starting at the battery, check voltage at the negative terminal, then again at the solenoid, again at the starter switch, and again at the resistor. From one end to the other, a total of 3/4 v loss is acceptable. The resistor drops 2 v, and you need no less than 3 v at the coil. With a good battery, that leaves you with 3 1/2 v at the coil, which is what you want to not burn up your coil. The biggest unwanted loss will be your ignition switch, which is replaceable and available from many vintage Ford suppliers.
 
Thanks Craig for the technical information! And Thanks Alan for the step by step diagnostic direction! I really appreciate you guys!!

I will be running through the checks this weekend to see what the voltage it at those locations.

Thanks again!

Kevin
 
As my spec chart shows, the voltage when tested at the generator terminal of the regulator and grounded on the bolt on the regulator where the generator ground attaches should be between 7 and 7.2 volts. Better checked there than at the battery. That's at 1375 rpms per the other chart. If you have a way to check amps (which I don't) you check that at the battery terminal on the generator and should be between 30 and 33 amps at 70° and 1060 rpms per the spec sheets.
 
Kevin, I hope you're not getting confused with two different sets of instructions from Old Henry and myself. We each are approaching from different perspectives, so don't equate one with the other but rather, focus on one set then the other.
 
ford38v8 said:
Kevin, I hope you're not getting confused with two different sets of instructions from Old Henry and myself. We each are approaching from different perspectives, so don't equate one with the other but rather, focus on one set then the other.
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Yes. Alan was addressing the ignition circuit and I was addressing the charging circuit.
 
This discussion echo's my complaint about dimming headlights on my recent '47 Ford purchase that came with 12 volt converstion and a GM alternator. Right or wrong, old timer who tested my system today said old 6v systems and my 12v alternator (with built-in regulator) do not charge at idle RPMs of 500. My Alt puts out nothing at idle and at say 2000 RPM it only puts out 12.8 under no load and only 12.5v under load .... which I understand to somewhat less than okay. Both my original and newer amp guages can show up to 30 amps at high RPMs - probably not good either.

I am noting the discussions and recommendations here as they may also help ID conditions re my situation. Thanks.
 
ford38v8 said:
Kevin, I'm sure you will both solve some problems and reveal some previously hidden problems when you replace that battery. the important thing is that you're proceeding in the right direction, and will get it all together this way. Get back at us with an update and more questions.
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Ok,

Here's the latest update as of today! Before I replaced the 8V battery with a 6V, and replaced the voltage regulator, all I ever did to start the car was pump the accelerator twice, pull the chock about 1/2 way out and the car would fire and start.

Now it cranks and cranks before starting (it's a good thing I have a new battery).

I wanted to take it for a ride today and see how the charging system acted but had such a hard time getting it started, then once I did get it started and warmed up, I drove it down the road and it was bucking and cutting out from time to time.

I am wondering if the coil may have went bad. The car previously ran pretty good but would occasionally cut out but I thought it may have been because the car was a little cold natured and wasn't fully up to running temp.

The car has a new distributor so I doubt the points are burnt, and I decided to replace the in-line fuel filter today as a precautionary measure.

Also, it's the craziest thing. I was going to use my craftsman multi meter to check the voltage at the battery and generator, but when I get under the hood of the car, and next to the engine, the meter goes crazy, displaying all kinds of numbers before the leads ever touch anything.

I checked the meter on a 12V battery and it tested fine, but don't like the Ford for some reason.

Kevin
 
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