H Model Ammeter shows no or very little charge

VFMerc · Nov 13, 2009

I have a 1953 H Model with a 6 volt system, magneto, 6 volt generator and 6 volt regulator (L/B/F) that I recently restored. When I run the tractor the ammeter shows no charging or possibly a very small charge. I've used the trouble shooting guide I found on line but can't seem to determine the problem. When the engine is off and lights are turned on the ammeter shows a discharge. When I start the engine and run at ½ speed or better, and place a voltmeter on the regulator F terminal I get 6.24 volts and the battery shows 6.1 volts. The ammeter shows no charge or perhaps just a little. If I turn the lights on, the ammeter shows significant discharge reading. Is it possible the generator / regulator is not putting out enough current to override the battery voltage?

I reversed the wires on the ammeter and confirmed the needle will swing to both sides of the "0". I pretty sure I've got everything wired right. I'm stumped.

El Toro · Nov 13, 2009

You should see about 7 to 7.25 volts with the engine at that speed. You are seeing just battery voltage. Bob M has wiring diagrams for troubleshooting these charging systems. He may post on here or John T. Hal

Anonymous-0 · Nov 13, 2009

I had something similar in addition to just trying to figure out the wiring. A couple of the guys here said to wire the "L" terminal on the voltage regulator to the light switch and another said to the ignition switch. Then the "bat" terminal to the battery, naturally.

It was pointed out the generator would put out more this way because the loading sensing in the voltage regulator would be more accurate.

Bob O2 Martin · Nov 13, 2009

I'm not the Bob M Toro is talking about.

rvirgil_KS · Nov 13, 2009

The regulator connections would be
L (load) goes to hot side of light switch (and ignition switch if using distributor)
B (Battery)goes to ammeter
F (Field) goes to Field terminal on generator
There should be an Arm or Gen terminal under the regulator. It goes to armature on the generator. Is this one connected, you don't mention it so I wonder if that is the problem.

The F (field) terminal should vary in voltage. Be more concerned with the Armature voltage as that is the generator output.

With all properly connected, if you ground the field terminal it should show full charge.

John T · Nov 13, 2009

If that Voltage Regulator is labeled L B F Id say underneath it has its ARM terminal SO YOU SURE ITS WIRED CORRECT??????

BAT on VR to Load side of ammeter
FLD on VR to Gennys FLD post
ARM/GEN on VR (underneath) to Gennys ARM post

LOAD feeds hot battery voltage up to the loads like lights and ignition etc usually via its being wired to those switches BAT input terminals

If the L terminal is not used loads can be fed off the load side of the ammeter (like on 3 terminal VR's) which is the same place that wires down to BAT on the VR

ONCE YOU GET IT WIRED CORRECT from the above or Bob M's Diagrams, then my Troubleshooting Procedure below will help diagnose the problem. The gennys output is on its ARM post but the open unloaded output of a genmy dont mean all that much. Its to what voltage it can raise a good batrery that matters. Id expect a 6 volt batetry to read 6.3 volts sitting there but if coupled to a good charging system at fast RPM the battery voltage should rise to 6.5 to 7 volts and a lil over.

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=farmall&th=665110

John T
John Ts Troubleshooting

VFMerc · Nov 14, 2009

(quoted from post at 01:30:11 11/14/09) The regulator connections would be
L (load) goes to hot side of light switch (and ignition switch if using distributor)
B (Battery)goes to ammeter
F (Field) goes to Field terminal on generator
There should be an Arm or Gen terminal under the regulator. It goes to armature on the generator. Is this one connected, you don't mention it so I wonder if that is the problem.

The F (field) terminal should vary in voltage. Be more concerned with the Armature voltage as that is the generator output.

With all properly connected, if you ground the field terminal it should show full charge.

Thank you. It is wire as you have indicated and yes the "A" terminal on the generator is connected to the "GEN" terminal on the under side of the regulator.

I did not know where / how to check the generator's output. I'll check the voltage at the "A" terminal of the generator with the engine running at 1/2 speed or better.

1. What should I expect to see on the ammeter with the engine running (lights off) if all is working properly?

2. Should I see a discharge indication with the engine running when I turn on the lights?

VFMerc · Nov 14, 2009

Thanks. I wasn't checking the gen output at the right location (A terminal) as one of the other folks pointed out. I'll check to see what the what I get at the A terminal and go from there.

VFMerc · Nov 14, 2009

Thanks John. I'll print out the trouble shooting guide and begin there.

H Model Ammeter shows no or very little charge

VFMerc

Member

El Toro

Well-known Member

Anonymous-0

Well-known Member

Bob O2 Martin

Member

rvirgil_KS

Well-known Member

John T

Well-known Member

VFMerc

Member

VFMerc

Member

VFMerc

Member

Similar threads