Letters next to light switch?

Livin the Dream · Aug 22, 2011

What do the letters next to the light switch mean? L-H-D-B

Anyone.....thanks

snoop-nc · Aug 22, 2011

L--low charge rate
H--high charge rate
D--Dim lights
B--Bright lights

gene bender · Aug 23, 2011

The decal goes on the left side of the knob with the "L" about the 7 oclock position. The poiner can be moved to line up on the decal.

JRSutton · Aug 23, 2011

Why would one use Low charge vs. High charge?

Somewhere in the back of my head I think it's about the time you're running the tractor - all day, leave it on low charge - quick job, put it on high charge.

Or am I completely wrong?

Athol Carr · Aug 23, 2011

The low charge, high charge rate switch was used on systems without a regulator, i.re. those with a cut-out relay. The regulator adjusts the charge rate to suit the state of the charge of the battery, when near fully charged, too large an input current will harm the battery. The high charge would be used immediately after starting, particularly if the starting process was protracted, to bring the battery quickly up to charge and then switch to low charge to keep it fully charged, or bring it up slowly in normal operating condition. If the lights were on the system is effectively in low charge automatically. If the is a voltage regulator then the switch position are lights off, dim and bright lights as the other features are controlled automatically by the regulator. The early systems used a cut-out relay, to ensure the current went from the generator to the battery and not in the reverse direction. The output control was left to the operator. IH apparently made the switch from cut-out relay to regulator in 1949. My 1948 Super-A has a cut-out relay on the generator.

Scotty HOMEy · Aug 23, 2011

You've got it right, just as atholl explained above.

That 4-position switch, has a resistor on the back of it to cut down the current for a low charge. The L(ow) is the only position in which current is passed through the resistor. In the H(igh) position, the resistor is back out of the equation, and the generator current has a straight run to the battery. In the D(im) and B(right) positions, still no switch resistor, with the light filaments taking the place of the resistor to limit charging current. (In the D(im) position, there is a second, separate resistor on the back of the swithc to limit the current to the light, which is cut out in the B(right) position.

(One result - if you see a higher than normal charge while your lights are on, look for a burned out bulb.)

Letters next to light switch?

Livin the Dream

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snoop-nc

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gene bender

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JRSutton

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Athol Carr

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Scotty HOMEy

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