Inside a JD 730 diesel electric start ignition/light switch

I opened the switch up on my converted 24 volt electric start John Deere 70. No, I didn't convert it. I bought it. Maybe someday it will become a pony start again. The conversion resembles that of a factory John Deere 730 24 volt electric start. I didn't think my switch was operating right regarding powering the push button to energize the starter solenoid. I see inside of the switch a little donut looking metallic disk probably the thickness of 5 or 6 dimes. I assume this is some kind of resistor. What does this interior metal disk do? My light switch also has two resister coils on the outside as well. I am trying to think whether this makes a high / low for the front head lights or is used for something related to reducing 24 volts to 12 volts so the lights do not burn out. Don't the lights on one side use one 12 volt battery and the lights on the other side use the other 12 volt battery so both batteries have the same drain? This issue is sort of related to John Deere 730's with 4 front head lights verse those with 2 front head lights. Do the 730's with 2 head lights on each side just shut one head light off on each side? Maybe the 730's with only two head lights must actually dim them? Can someone straighten me out? Thanks.

(quoted from post at 18:23:37 05/14/20) I opened the switch up on my converted 24 volt electric start John Deere 70. No, I didn't convert it. I bought it. Maybe someday it will become a pony start again. The conversion resembles that of a factory John Deere 730 24 volt electric start. I didn't think my switch was operating right regarding powering the push button to energize the starter solenoid. I see inside of the switch a little donut looking metallic disk probably the thickness of 5 or 6 dimes. I assume this is some kind of resistor. What does this interior metal disk do? My light switch also has two resister coils on the outside as well. I am trying to think whether this makes a high / low for the front head lights or is used for something related to reducing 24 volts to 12 volts so the lights do not burn out. Don't the lights on one side use one 12 volt battery and the lights on the other side use the other 12 volt battery so both batteries have the same drain? This issue is sort of related to John Deere 730's with 4 front head lights verse those with 2 front head lights. Do the 730's with 2 head lights on each side just shut one head light off on each side? Maybe the 730's with only two head lights must actually dim them? Can someone straighten me out? Thanks.

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"I see inside of the switch a little donut looking metallic disk probably the thickness of 5 or 6 dimes. I assume this is some kind of resistor. What does this interior metal disk do?"

Have we talked about this before? (I replied to someone with a similar question recently.)

There's a resistor like that (typically on the outside) that allows the use of a 12 Volt lamp for the generator indicator lamp. (Generator circuit is 24 Volt.)

Does your switch have another "disc" resistor on the OUTSIDE, as well or just the one?



"E" in the drawing is the resistor on the 2-lite switch for the generator light, you can see what terminals it;s connected to.

The other resistors on your switch are for headlamp dimming.

"Do the 730's with 2 head lights on each side just shut one head light off on each side?" I believe so, as i recall, they use different lamps, I believe one of each pair is a sort of hi-beam that gets shut off on "dim", and the other is a lower-focused "flood".

"Maybe the 730's with only two head lights must actually dim them?" Yes, with the wire coil resistors you've noticed.

"I didn't think my switch was operating right regarding powering the push button to energize the starter solenoid. "

NOT sure what you may have going on there, but the "A" and "B" battery connections on the switch have to be connected to the appropriate batteries and in the correct relationship to the starter solenoid for the combination switch and the pushbutton to work together to operate the starter.

Could you draw a diagram and post it, as to the details of how yours is wired?

Think of the 24 volt system as 2 separate 12 volt systems. 1 is pos. ground and the other neg. ground. This is to balance the load out.
I have had many switches apart ( 12 volt ones ) and the only metal thing inside of them I remember is the part that acts as the contacts when you turn the lever. I don't remember having the 24 volt ones apart though ? They usually get pretty fried too. Resistors were mounted on the outside on back of switch. Some for lights and if a pony motor there is to be one for the coils too, but many of them are missing that one.