John Deere 720 gas wiring help needed

Purchased this tractor with alternator -2 wires -
Trying to follow wiring diagram for instrument panel - here is what's going on-
-former owner had sub wired kill switch since main switch would not work in ignition mode
reconnected switch to test -worked, but the battery goes dead -must be internal short in switch -bought new switch
-found bare spots on original battery cable that are green and touching steel sheath -have removed and getting new cables
-wiring arrived here as follows-
1.- starter wire to resistor -good
2.- other side of resistor - green wire to positive terminal on coil - second wire to fuel gauge
3.- alternator -yellow wire from bolt on alternator to ampmeter -jumper wire from bolt on alternator to spade connector on side of alternator-voltage regulator?-red wire coming off of spade beside jumper wire to battery screw on ignition switch
4.- brown wire from ignition terminal on switch to positive terminal on coil
5.- negative terminal on coil wired to terminal on distributor -no other wire on terminal
6.- The switch I purchased is the same as the one that was on the tractor -there is no MAG terminal for wire from switch to positive terminal on coil -as per what the manual says
---the other wires appear to be as per manual
I am figuring the former owner had the tractor set up negative ground --that is how it was when I purchased it -
I will keep the alternator for now as the tractor charges good(as per ampmeter)

Any help would be appreciated

Ken

I forgot to mention -there is a diode in the red wire that goes back to the battery terminal on the switch
Ken

Ken;
Could you please explain what you think is wrong? All I get is there is no MAG terminal on the switch. You don't need one. That terminal is only used on magneto tractors & it is just a ground to kill it.

Mag terminal -the wire that is listed -brown -is between ign terminal and positive terminal on coil

It should be there to stop the alt backfeeding.

Coil is supposed to be powered by ign so it is correct.