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Bolters -

Need a little help in diagnosing a recent issue. Have a 54 3100, still 6v. All was fine, until recently, when driving the ammeter pegs to Charge. If I come to a stop then at idle, ammeter moves to center. There are moments when it will fluctuate from the center to the far right, but mostly likes to sit all the way to the right.
Generator and Voltage regulator are re-built/new. When put back together about 10 months ago all was well. No other electrical issues, truck starts right up every time.
Appreciate some guidance on figuring this one out as
Electric issues for me are always challanging.
Thanks
Joe

After start it will show a hard draw for a while to recharge the battery. Assuming you know that and you've driven several miles to allow the recharge, it sounds to me like you have a serious current load going on. Something pulling a lot of juice. The ammeter will drop at idle simply because the generator can't put out more at idle. I'm certainly no expert but if it were me I'd put a known good ammeter in the circuit and see what it says. If it shows a 25-30 amp draw when running you have some investigative work to do. Good luck.

Pull the cover off the regulator and check to see if the voltage regulator points (directly behind the Field wire) are stuck together. If not, disconnect the F wire from the regulator and see if the ammeter continues to peg out. It should not move at all with the F wire disconnected unless there's a short to ground somewhere between the generator and the regulator in the field circuit, or a shorted field winding inside the generator. If the heavy current continues with the wire disconnected at the regulator, disconnect it at the generator and repeat the test. When you find the source of unintentional ground, replace the wire, the regulator, or the generator.
Jerry

Edit: It's also possible that the battery has developed a shorted cell and it's the cause of the heavy charging current. Swap a good-condition fully-charged battery into the circuit before you start chasing other gremlins.

You might want to take voltage readings at the GEN and BAT terminals with the engine running above idle. If the regulator has failed causing a maximum generator output, it could boil your battery dry.

My next project is my very first project. A 1950 3100 with 216 100% original. I personally hate generators and regulators mainly because I know nothing about them. Yet, as an electrical technician/engineer all my life, I am interested in how they work. I would LOVE to see someone make a how-to on troubleshooting this system, the specs, the readings expected, what to do, etc. Someone get to it!

Thanks everyone for the input. Here is an update

Checked all electrical connections from battery to generator to regulator. All seemed fine. Pulled cover off regulator and checked contacts. Though touching, none were stuck together.

Pulled field wire and started truck. Pulled throttle to well above idle. Ammeter did not move. Put back together.

Reading at battery above idle was 16.5. At regulator 16.8 to 17. Regulator bad? Or do I adjust?

Thanks
Joe

This is a 6 volt system? I think your "new" generator and regulator just might be 12 volt items! 6V charging voltage must not be above 7.5 volts. Even if it's running a 12V battery, 14.7 volts should be maximum, and that's against a fully charged battery.

Until we're on the same page about battery voltage and such, the readings are way too far off the wall. Find someone in your area who knows what he's doing and let him sort things out. I don't think it's possible to do enough adjusting to fix this one! My email address is in my profile, but I'm not sure if you have access to that part of the website yet. If so, drop me a note and we can do a telephone consult.
Jerry

Deve, based on our previous interactions, a tutorial would be a total waste of time. You would nitpick and argue about everything. I have an excellent early-1950's Delco instruction manual on DC generators, starters, regulators, etc. that I would be glad to scan and forward to you if you like.
Jerry

I wouldn't argue with someone who knows as much as you, but I would ask a lot of questions so I would be sure to understand it. That's the hard part, not being as smart, I need to fully understand. Don't use ME as an excuse not to do it. There are lots of people out there who would benefit by the looks of the forum traffic over the years. Scan and forward. No hurry since it will be a few years before I am ready to tackle my 216 project.

Actually, I started a series of articles on DC charging systems in the tech tips area, finished the first one, and a heart attack interfered with getting the rest of them written. I think it's still there. If I ever get a "round tuit" maybe I can expand on that series!
Jerry

Most of my friends are between 70 and 90. They come to the shop just to see how I am doing, because they see themselves at my age in the enthusiasm and work ethic. Its a challenge then for me to live up to their high standards, but I listen and hope that someday I can offer the great advice and counsel I was given. But, there HAS to be some element of coming to watch the dumass get in over his head! I am just honored by the elders who have done so much for me over the years. You have all the machine shop equipment to make your very own round tuit.

Generator checks out good.

Voltage regulator was bad

Swapped it out and all is well

And yes, it is a 6v system