Heallight_work

William, I originally drew that diagram and it is for a 1923 to 1925 head light switch mounted on the back of a headlight.

What Jim Cuddihy needs is the 2930-26 main bulb focus tube.
Look in the parts book and it is listed for 1926 to 1928 JD headlights.
A single filament main bulb goes into it, I believe #1133 double contact, no-ground at the body (special.) The hot-wire goes to it and it is above ground with the ground wire going back to the headlight switch in the dash and is grounded only when the switch it on hi-beam.

It is confusing and why they did it that way is beyond me. There is another hot-wire from the this hot side on the hi main bulb to the other single filament dim or park bulb.The head light stem in the dash has to ground really well to the dash housing for it to work. Crazy but I don't lie.

mine. The glass is shower door glass from a local glass shop. (I thought it made more sense to have the glass ridges running horizontally.)	picture from somewhere showing glass 2007 image of reproduction headlamp from New Zealand

bulb - 6 volt H3 type. 25 watts via eBay
15 Jan.2020 - from Joe Drociuk: William, I originally drew that diagram and it is for a 1923 to 1925 head light switch mounted on the back of a headlight. What Jim Cuddihy needs is the 2930-26 main bulb focus tube. Look in the parts book and it is listed for 1926 to 1928 JD headlights. A single filament main bulb goes into it, I believe #1133 double contact, no-ground at the body (special.) The hot-wire goes to it and it is above ground with the ground wire going back to the headlight switch in the dash and is grounded only when the switch it on hi-beam. It is confusing and why they did it that way is beyond me. There is another hot-wire from the this hot side on the hi main bulb to the other single filament dim or park bulb.The head light stem in the dash has to ground really well to the dash housing for it to work. Crazy but I don't lie.