H Charging Problem

I have rewired my '51 H in accordance with Bob M's wiring diagram. I have a 6 volt positive ground system with a brand new 6V regulator. The genny is off of an early '50's Chevy. It is a 6V unit and has been checked out by a local genny shop and declared OK. I have a 3-position O-D-B light switch.

Here's my problem. When the tractor is running, I get no indication on the ammeter that the charging circuit is functioning.

I asked a local mechanic to backcheck my work and see if he could get the charging circuit to engage. After verifying that all was wired correctly, he installed a jumper wire from Terminal 3 on the back of the light switch to the GEN terminal on the VR. With the engine running, he then switched the lights on, and then immediately back off, and the ammeter instantly showed current. He said I should leave it wired that way and just run it. That solution does not seem correct, because when I run it the lights stay on even though they are switched off.

Can someone help me resolve this problem so that the charging circuit works without the jumper wire/lights on condition?

Thanks for the help.

A bad regulator ground will do that, as will a regulator with an improperly adjusted pull in voltage. Clean the ground first, then try a different voltage reg. Jim

Doug - that's an odd one! Suspect the problem is a mismatch between the voltage regulator and the generator.

Wiring the GEN terminal to #3 on the light switch is a kluge. The effect system on regulation is unpredictable as evidenced by constantly burning lights with the engine running.

For the electrics to work right - also to not risk ruining the generator - you MUST use a regulator for the make & model Chevy your generator came from. A regulator for a stock H will not work!

Before you pursue further you need get a matching VR and generator(!)

Think Bob M has it.

IIRC the 50's Chevy used a TWO brush gen and a THREE unit reg. The stock H setup if it had a VR and not a cutout would have been a THREE brush gen and a TWO unit VR.

The Chevy gen would have been higher output than the stock H gen and would draw too much field current for the points in the stock H gen.

Don't ask how I know these things. BTDT.

Id guess the genny is compatible, heck its 6 volt and can work at EITHER Polarity so Im inclined to think its EITHER a VR (maybe mismatched) or like Jim the VR isnt well grounded.

Id wire it back correct (undo that jury rig),,,,,,,,,Polarize the genny just to be safe,,,,,,,,Then when running take a jumper and dead ground the gennys FLD post n see if she charges then??????????? If so but not otherwise (means the genny itself is fine), the VR is bad or its not well grounded, or its just incompatible with your genny.

VR's for later 2 brush gennys (like the Chevy) and older 3 brush (early H tractor) just arent quite the same and Im not comfy mixin n matchin those due to different field currents and voltage levels etc. The smaller 2 coil VR's (used on 2 or 3 brush gennys) had a cutout and maybe either a voltage or current regulator (or a combination) while the 3 coil VR's (more for 2 brush gennys) had a cutout, a voltage regulator and a current regulator.

Id agree with my friends you need the correct VR unless its just not grounded

SURELY?????? the VR is for a Class A and NOT a Ford Class B I tried that mix match once years ago before I knew better, it didnt work either lol

John T

One other thing, unless you use an extermely small pulley on the gen, that slow speeded H will not spin it fast enough to charge until you rev up the engine quite a bit.