As I said earlier in this thread I had similar issues with my charging system. Also 6v pos ground all stock components. Besides having badly rebuilt generators and two bad regulators and a NOS regulator that got burnt out but eventually repaired. The one problem that we attributed to much of this was a badly corroded brass bus bar that connects the two circuit breakers behind the dash. The front was clean the back was bright verdigris green.




also of note I found the 1951 ford truck forum series more useful and easier to understand than the manual.

particularly this booklet. Although the whole series is very useful.
https://ebay.us/m/CKEBB3

 

And another question:

When you full fielded your generator. Where did you hook up the battery side of the test cable to? Did you run a seperate wire back to the neg terminal on your battery, or did you just connect it to the BAT terminal on your voltage regulator?

 

The last test I just ran was running the arm right to the negative, but I’ve also had it fully fielded and touched the regulator bat terminal.

 

Thank Lando!

So it sounds to test good the same both ways. The reason I asked was to see if you were seeing a "ghost voltage" at the regulators battery terminal. A ghost voltage occurs when your modern digital, high impenence, voltmeter sees a voltage, but, when applying a load to the circuit like an old fashioned incandescent test light, the voltage will go away or will dramatically decrease due to a high resistance loose/bad connector, a damaged corroded piece of wire or electrical component like bad switch/relay contacts. The multimeter will be so sensitive it will still read the voltage, but when an actual current drawing load is connected the voltage will just dissapear or will be so low that whatever the load is will not function. So I was thinking you may have the same issue that 52Flthead had. That is a corroded/ bad/loose connection back at the circuit breakers bus bar where the Bat connection to the regulator connects to the wire that runs to the solenoid, where it picks up the battery negative voltage. But it sounds like you verified thats not going on here as you could use the yellow Bat terminal regulator wire to full field test your generator and send 30 amps to your battery.

Where would I go from here? I would probably write up everything you tested, and take the Generator and voltage regulator and your notes back to the shop you used earlier, and tell them that on your truck, with the generator and regulator installed correctly, and even with polarizing, 3 amp open field testing, 30 amp/8 volt full field testing, troubleshooting with test jumper wires, grounds tested, with that generator, you can not get the the cut out relay to pull in and get the charging system working. Tell them how your tested your voltage regulator cut out with your variable voltage power supply. Also tell the that while its operating on your truck, you are only seeing 4 volts on the Armature. Maybe while your there they will put it on their test rig, and see it for themselves. If they dont test it while you are there ask them to note for you what voltage the cut out relay does pull in at and what the RPM is when it does.

I know a good gen guy in Washington state. If these folks can't help you, I know he can. You would just have to box it up and ship it to him. Let me know and I can give you his contact information.

Anyway this is just my take.

 

Just for S&Gs I did look at the back of the cluster to verify the connections. The cluster was restored and tested so I wasnt concerned about corrosion, but it was still worth checking.

 

The Jegs link takes you to a 12v one but just search on 6v positive ground one and it will come up. It looks like it is part number Power Master 82106 or 82056. They are listed as GM but I am guessing that is based on the case size.

At this point how much are you going to pay to ship it both ways to have someone fix it? Pretty close to $300 or maybe more I bet. If it were me I would switch to the 6v 1 wire alternator above. Once and done, hassles are gone, and you have better cleaner power to your headlights and anything else that needs it. From what I have been able to research your ammeter will still work with it and it is simple plug and play.

FWIW I still have my 6v set up but if it fails that is what I will do. It's tempting to do it anyway but I am not working so I have to limit things to the must haves right now.

 

I have switched 3 of my generators to alternators and I have had no further problems.

 

Probably not the resolution people were hoping for, but I ended up buying a powergen alternator and she now charges at 7.2 volts at idle.

Thanks everyone for their help.

 

Hey Lando!

A win is a win and I am glad you got your charging system working. Glad you hung in there.
Thanks for letting us know!

EDIT:
PS,
You probably know this already. I don't own one but from what I understand one wire alternators have been known to have a little parasitic current draw to them. So when your truck is not running a very small amount of current is being drawn out of the battery through the alternator. In the low 10 milliamps range. I would keep using a battery tender/ low amp charger on the system if the truck is going to be sitting a while.

 

Thanks for the heads up. That's probably enough draw on a 6 volt battery where it cant sit for an extended period of time.