light switch

I need to replace the light switch on my Super A. I have changed over to a magneto, 12volt system and alternator. The switch I'm replacing is 6 volt 4 position. I will replace with a 12 volt but should it be a 3 or 4 position switch? Can someone explain the differance between the
3 & 4 position switch?

(quoted from post at 00:07:50 12/19/10) I need to replace the light switch on my Super A. I have changed over to a magneto, 12volt system and alternator. The switch I'm replacing is 6 volt 4 position. I will replace with a 12 volt but should it be a 3 or 4 position switch? Can someone explain the differance between the
3 & 4 position switch?

Click to expand...

The 4 position on the older switches like that were as follows: LOW CHARGE, HIGH CHARGE, DIM LIGHTS, BRIGHT LIGHTS

The 3 position switches are as follows: OFF, DIM, BRIGHT

The "Low Charge" and "High Charge" don't have anything to do with the lights themselves, but the charging system. You can use the switch you have, and it will work just fine. There is no need to replace it with a different one, unless its defective.

Ill give it a shot:

QUESTION: The switch I'm replacing is 6 volt 4 position. I will replace with a 12 volt but should it be a 3 or 4 position switch?

All you need is a 3 position Light Switch, Off Bright Dim. Youre ONLY turning lights on or off NOT regulating a generator charge Low or High like the 4 position LHBD switch does on Cutout Relay systenms that DO NOT have a full fledged Voltage Regulator. No need for a 4 position LHBD, although it can still be used to turn lights on or off ignoring the Low and High Charge uses.

QUESTION
Can someone explain the differance between the
3 & 4 position switch?

The 4 position LHBD was for systems that used a Cutout Relay (NO Voltage Regulator) so the Low and High positions manually regulated the gennys charge by connecting the gennys FLD to ground for High charge but through a resistor on the switch for Low charge.

The 3 position switch Off Bright Dim was for gennys that used a VoltAGE REGULATOR it controlled lights ONLY not genny low or high charge as the VR did that.

Are wiring an On/Off kill switch for the Mag???


If I missed anything the other fine gents will hopefully add more

John T

Thanks John & RTR. I will replace with a 3 position 12 volt switch.

(quoted from post at 12:19:40 12/18/10)

(quoted from post at 00:07:50 12/19/10) I need to replace the light switch on my Super A. I have changed over to a magneto, 12volt system and alternator. The switch I'm replacing is 6 volt 4 position. I will replace with a 12 volt but should it be a 3 or 4 position switch? Can someone explain the differance between the
3 & 4 position switch?

Click to expand...

The 4 position on the older switches like that were as follows: LOW CHARGE, HIGH CHARGE, DIM LIGHTS, BRIGHT LIGHTS

The 3 position switches are as follows: OFF, DIM, BRIGHT

The "Low Charge" and "High Charge" don't have anything to do with the lights themselves, but the charging system. You can use the switch you have, and it will work just fine. There is no need to replace it with a different one, unless its defective.

Click to expand...

Exactly. Use what you already have, but make some different wiring connections.

This may be a dumb question, but in what case with the 4 position switch, would you want to use a low charge?

(quoted from post at 13:42:50 12/18/10) This may be a dumb question, but in what case with the 4 position switch, would you want to use a low charge?

Click to expand...

The 4 position switch was used with the cut-out relay which did not automatically regulate how much charge was being put into the battery, so if you were using the lights, the high charge position was used, and if using the tractor WITHOUT the lights, the low charge position was selected to prevent overcharging the battery and boiling it dry. I sometimes use the high charge position on my 1940 H if I will be running the tractor for only a short time, because it will more quickly replace what is lost in the battery from just starting, but the low charge position is always used when using the tractor for an extended period. The ampmeter is a good indicator of which setting to use.

Its NOT a dumb question, its a very good and legitimate one in my opinion. Theres no dumb questions, just dumb answers now n then lol

Low charge would be appropriate if youre running for long longgggg hours at high RPM and not using lights (but if you are the switch makes her high charge anyway) otherwise you could over charge the battery. Starting is a huge load, so if you start her up but only use it a short period, now thats a good time to use HIGH Charge.

Your question was certainly a good one I hope my answer measures up

John T

Youre welcome, No problem, a 3 is all you need if youre replacing it anyway, like I said you could still use a 4 position (to control lights only) and just ignore the Low High positions.

John T

rustyfarmall spelled it out but, to put in in a different order . . .

The only position that was low charge was the L position. H and both the D(im) and B(right) all three were high charge. Any time you were burning lights, you would be connected to the high charge rate.

As for the L and H positions, those were both without the lights running and the operator was basically the human voltage regulator. For the most part, L would actually have been the most used position.

If I were firing up the tractor one fine summer morning to head out for a full day of cultivating beans, I would select the L(ow) charge rate. With a magneto, there would be no draw on the battery at all after starting and to drive the full charge rate for a ten-hour day of cultivating would go a long way toward boiling off the battery. Even with a battery ignition, the draw is very low and the low charge rate is sufficient to keep up with the ignition demand and also restore what was lost, as teh long as the tractor is up to speed and working.

To choose a high rate, it might be for a short run, say just moving the tractor to put it away. Another scenario might be on a tractor that I was confident of the connections being good and that normally started okay. If it had been sitting for a long time and started hard, I might give it five minutes or so on high before dialing back to low for the rest of whatever I was doing. (Trick there is remembering to dial it back to L!) A third example would be if I was using the tractor for lighting up something I had to work in the dark and out in the field. My choices would be to run the tractor at enough speed so that it was also giving a light charge while running the lights. If I were to see that I had been running at a slight discharge because I didn't have the genny turning at high enough rpms to overcome the load of the lights, I might run it on Hign while I drove it back to the shed. (Again needing to remember to dial it back to Low so I wouldn't accidentally overcharget the battery after the next start.

In short, for me anyway, L(ow) is the default setting, and H(igh) for the odd situation when it's needed.

Thank you guys! I always wondered. My M and H are always on High Charge..now I guess I will switch to low if I use it for long periods of time.

Yer welcome.

These machines are pretty simple, which makes them fun and comparatively easy to work on. But when it gets down to having to regulate your own charge rate by hand, well, that's outside the experience fo a lot of folks.

Myself, I thought it was a pretty good question.

And here I thought the 4 position switch on my 2606 was off, low beam, high beam, and high beam with rear light. Anyway that is how I wired it. Seemed like it charged better with lights on but that should be normal.