Has anyone got a tech manual for a 30 Series tractor to tell me what empty/full range a RE221715 sender uses? The parts listings don't seem to have the info they used to provide.
Gauge....MT=1 ohm, 1/2=44 ohms, full=88 ohms
Sender...MT=0 ohms, 1/2=45 ohms, full=90 ohms
TM1058, 4630, 1974, factory manual.
As for wiring, negative ground is negative ground...so unless something isn't wired right no reason the components won't work from the newer 20 series.
When you rewired yours over to 12 volts, you went thru everything? For many years Deere did have a kit, everything from harnesses, alternator and starter all in one box, but I haven't seen or heard of them in a while now. Years back a neighbor put one in a early 4020 and I seem to remember there was something screwy with how the fuel gauge was wired but I can't remember what it was now. I'm thinking there was some resistor that had to be installed if you was using the old components perhaps. But if when you made the change to 12v, anything that was tied to that stupid double system of one system postive ground and the other negative needed to be changed. As for example the lights were split between the two, to balance the charge rates on each battery and this was all done thru the light switch itself.
Gotta be something simple you are over looking. Happens to us all at times, hope you get it figured out.