1950 H Charging system

[wilsonsk]

It has the 4 position L-H-D-B switch, and I'm assuming a cut out, it's big and square like a regulator, but appears to have 4 terminals, and one on the right side isn't used, just one wire going up to the box. It charges a little with the switch on H, but won't keep up with the lights, after running for a few minutes on H wide open, I get about 6.2 volts, ammeter shows a slight charge. I'm assuming it should be better than this.

Any help???

Thanks,

STeve
 

[wilsonsk]

Here's a pic of what I have on top of the generator. What should I have for voltages running wide open, no lights, high charge? Oh, and there are two wires going to the switch box.
 

[wilsonsk]

 

[wilsonsk]

 

[wilsonsk]

Have another update, I tried a few things...

Polarizing, no real improvement.

Cleaning up the switch box and getting a good ground to the light switch - This got me from 6.2 volts to 6.5 volts on "H" setting, still discharge and less than 6 volts with lights on "D" or "H".

"Snapped" the brushes while it was running (pulled them away from the aramture and let them snap back, not sure if this is a good thing or not, but thought I'd try it) - This helped the most so far, got me up to 7.2 on "H", about 6.2 on "D", and about 5.8 and slight discharge on ammeter withthe lights on "B".

I would imagine I should replace the brushes, is there anythng I can do to clean the armature?

Thanks,

Steve
 

[John T]

Normally and originally if it had the LHBD switch that controlled the Low or High charge rate and there was only a 2 terminal (a few had 3) Cutout Relay on the genny instead of a full fledged VR. The gennys FLD wired up to the LHBD and the gennys ARM wired to the cutout realy

I only saw 2 terminals and only one relay/coil on that box (would make it a Cutout Relay NOT a Voltage regulator). Id say the wirewound resistor you show is for the cutout relays shunt......

Its very important that BOTH the Genny and Relay PLUS the LHBD switch have good clean bright shiny to case frame grounds.

When shes running dead ground the gennys FLD post (NOT the post to the relay, thats the ARM post) n see if she charges then?? If so but NOT otherwise, the wires bad from FLD up to LHBD switch,,,,,,,or LHBD has a bad ground,,,,,,,or perhaps the LHBD field current resistior is bad/open, but even it were and it had a ground it could still charge cuz that field resistor is ONLY used for Low (L) charge.

A good 6 volt battery ought to read 6.3 volts when setting but when the tractor is running at fast RPM a good charging system takes the voltage to 6.5 to the 7 range.

WORK THROUGH MY TROUBLESHOOTING PROCEDURE


http://www.ytmag.com/cgi-bin/viewit.cgi?bd=jd&th=458743

John T
John Ts Charging troubleshooting

 

[Bob M]

With the engine running wide open and the light switch set to "high charge" (H) you should see between about 7.0 and 7.5 volts at the battery.

Keep in mind if the generator is original, max output can be increased by moving the adjustable 3rd brush closer to the nearest fixed brush. (Adjust by loosening the clamp screw on the commutator end of the genny and reposition the brush holder as required.)
 

[Bob M]

That resistor and the associated F terminal are used only if the tractor has no lights. (With no lights the generator FLD terminal gets connected here instead of to the light switch field terminal.)

Do not connect the light switch field control this terminal! Doing so reduces maximum generator output to about 3 - 4 amps in the H, D and B positions, and to almost 0 amps in L.
 

[John T]

Cool, I just learned something, thanks Robert. I knew some of the IHC's used that setup but not sure which ones

John T
 

[Crazy Horse]

OK, so I have a Farmall A where the tractor has no lights but still has the 4-position charge control/light switch on the dash. I also have a 3-terminal box on top of the generator with one tower inside with the GEN and BAT terminals at opposite ends. The F terminal on this box seems to go nowhere unless hooked to ground through that resistor shown on the photo in which case it would go to ground if hooked up. What harm is done if the field circuit is wired from the generator case field post to the light switch? Even with no lights, then I would at least have the first two positions of the switch to control battery charge rate (which I wouldn't have if I went through the F terminal on the relay box) .... is that right?
 

[Bob M]

Must be your A came from the factory equipped with lights - otherwise it would not have the LHDB switch.

That said, what you are proposing (wiring the gen F post to the field resistor on the light switch) will work fine. In fact it's what I'd recommend as it will give you a means to control the battery charge rate.

Go for it!