Generator

KB1: installed 6 volt Halogen headlights and the generator puts out just enough amperage to bring the gauge just shy of middle line. I am hoping that there’s a higher output generator that will handle the new lights.

Generators in that era came in several amp capacities. Std was 30 amp, then there was 42- and lastly 48-50 amp (which is rare)
1st order is to make sure the regulator is allowing the generator to produce the full 30 amps, which should be enough, abit just barely. two 55/60 watt (low/highbeam) draw 10 amps each on high, so 20 amps total. Leaving another 10 amps for ign and the rest of the lights. (which likely are less than 5 amps total.
So first put an ammeter in the output of the generator and turn on everything and raise the RPM and see if the regulator is allowing the generator to put out 30 amps. The truck ammeter only shows what is going to or coming from the battery, not how much the generator is putting out.
With a generator system, the regulator controls how much current the actual generator is allowed to put out. Changing the generator without changing the regulator will not change a thing.
A mis-adjusted regulator could allow a 30 amp generator to put out 60 amps, but the generator would burn up in short order. Conversely a mis adjusted regulator can hold a 30 amp generator to 20 amps as well.
I found my 30 amp unit able to keep up at speed with 55/60 halogens and heater/wipers going, but just and only at road speed, not at idle where little charging will take place with any of the generators.

CB, thanks for your reply. I know that assuming is dangerous so please bear with me; to test the generator output I am to attach a meter lead to the “A” contact on the generator and then to a ground ? Or just across terminals ?

2nd question; if I find 30A or less output would it would make sense to upgrade to a higher output generator ?
The regulator was new and installed about one thousand miles ago, seems every thing is fine with standard beams but would like things a bit brighter ( especially as I age). Saying this with a little chuckle.

Thanks,
Bob

You can re-adjust the regulator so you get 30 amps, you could go a little over if needed, but once you go over by 10% or more you risk overheating the windings.
To read generator max output, you have to load the system so that current is what limits the generator. It can be done with a carbon pile, or by turning everything on.
Either a clamp on ammeter over the armature wire or an ammeter placed in series (not to ground) will show the output. You need to raise the speed. If you watch the ammeter you see it start to bounce, that is when it reaches the setting.
I should back up a bit and explain how the regulator work. There are three "bobbins" or "relays" under the cover. One disconnects the generator when it is not makeing power so it doesn't drain the battery (a generator will act like a motor if connected to power) One limits the amount of field current based on the voltage (voltage regulation) and the last limits the field current based on the output current.
With a fully charged battery, the voltage regulator will be the one that controls the generator as very little output s required to keep the battery charged with just the ign drawing current on the system.
With a low battery or a a heavy draw, the voltage regulator section goes to "full field" calling for max field current to try and bring the voltage up. To prevent the generator from burning itself up, the current regulator takes over and limits the output to a safe level regardless of voltage.
You can adjust these two regulators independently. The voltage should be set for a max voltage of around 7.2 or 7.3 with a full charged battery.
With a full load on the system, the voltage will be below the voltage regulator setting so it will call for full output, the current regulator can then be set to limit the output to match the generator rating.
Both regulators are adjusted by adding or removing spring tension on the movable arm, by bending the tabs holding the spring. Increasing tension raises the setting (current or voltage) decreasing the tension lowers the setting. It doesn't take much to make a big change.
The manual should provide the needed info
I have seen the manual only list the Std generator, but my '48 is all original and has a 50 amp unit on it and the ammeter in the dash is a 50-0-50 gauge. My '42 had a 30 amp unit and 30-0--30 meter.
The 50 amp is much bigger than the the other generators, having two pole shoe screws for each pole shoes through the case. The 30 amp unit is all one diameter with a brush band cover over slots in the rear of the housing for access to the brushes. The 42 amp unit larger at the front then the back and has no brush band cover and the back has opening for access to the brushes.
The design of the generator determines the safe output current. The regulator holds the generator to its safe level, they work as a pair, replacing one without re-setting the other to match, will not get you any change.

Thanks CB. I have a 30 amp generator. The truck will maintain center line or just slightly below on dash gauge with everything on and the rpm up. The regulator is fairly new and seems to be ok. I will attempt to do the tests today.
How badly can I screw up the regulator tweaking it ?

Would a 6 volt alternator be a good upgrade? I would, of course, keep the generator to be reinstalled for originality . OR reinstall the original headlights and hope I can see well enough at night.

I prefer originality, so I would keep the generator.
I had an alternator on mine at one time (the truck came with a 12 volt "conversion') so when I switched back to 6 volt, I had to do something.
I had a 78 amp Delco alternator, that when fed 6 volts into the 12 volt field, would put out about 30-35 amps.
Adjusting the regulator is just bending a tab to increase or decrease a setting. The hard part is keeping the load and speed at the point so you know what you are adjusting.
To set the amps, the generator needs to be turning fast enough, and the load high enough to be able to exceed the rated current. You then adjust the regulator to cut back the output to the current amount. Conversely when setting the voltage, the load must be light enough that the voltage would rise above the desired set point.
The regulator has three "bobbins" or relay's one has both heavy and light wire on the bobbin, this is the reverse current relay or cut-out,and you shouldn't have to adjust that one. Next IIRC the middle bobbin has heavy wire wound on the bobbin, and this is the current regulator, last with just fine wire on the bobbin is the voltage regulator.
To raise the current output, you add tension to the spring on the moveable arm, to lower you remove spring tension. Same with the voltage, more tension= higher voltage, less, tension= lower voltage.

Tested voltage at 7.6. Could not check amperage as the meter I have is a shunted system that is not easy to hook up with the battery under the floor. I’m sure I could get creative at some point. Running at about 1200 rpm ,with lights on , the gauge held steady between +-. I’m going to do a pretty good run with all on and see what happens.

7.6 at the battery would be a bit high. It would be like a 12 volt car having a charge voltage of 15.2, 7.6 at the generator but lower at the battery shows there is a voltage loss in the wiring.

Right again. Just checked the meter and where the needle pointed was at the top of the green zone (7.3). Guess all is well.