850 Ford wire harness

I replaced the wire harness on an 850 Ford tractor. It starts and runs but will not turn off when the key is turned to the off position. Was no instructions with harness but used schematic I found on the net. It is a 6 volt system with a generator. While running, the ammeter reads at zero or slightly to the neg side of zero.

Sounds like a bad ignition switch.

I wish I could delete this post. There is more that could be wrong (in wiring) than my solution.

You may have it wired wrong; such as the coil primary wire is hooked to the always hot side of the terminal block.
If you have it wired right your key switch is most likely stuck in on position.
I have included a correct wiring diagram.

Thank you John in LA for the schematic. Several questions, if I may? Is the low tension wire from the distributor to the coil connected to the (+) or the (-) side of the coil? At the ammeter, does the line from the coil connect to both terminals of the meter or is the connection shown on the schematic an overrun of ink?

Thanks Greg, replaced the switch and your assumption that it is something other than the switch is correct.

Is the low tension wire from the distributor to the coil connected to the (+) or the (-) side of the coil?

The distributor is the path to ground.
So the primary (low tension) wire from the coil to the distributor always hooks to the the same side of the coil as your battery ground.
Since you are running + ground at the battery the + on the coil gets hooked to the distributor.

At the ammeter, does the line from the coil connect to both terminals of the meter or is the connection shown on the schematic an overrun of ink?

Look at the diagram very carefully. The wire from the coil does not hook to the amp meter. But yes the ink spot between the 2 post on the amp meter is a ink over run. I got this diagram from a old book.

Since the diagram my be hard to read let me list the wires.
+ coil to dist
- coil to terminal block
One side of key switch to one side of terminal block.
Other side of key switch to other side of terminal block.
Terminal block to one side of ammeter
Other side of ammeter to starter relay where wire from battery hooks
B on voltage reg (V/R)to terminal block.
G on V/R to a good ground.
Another wire on G to ground on generator
A on V/R to A on generator
F on V/R to F on generator
Small post on starter relay to push button on top of trans.

Once again, thank you. I will recheck all of my connections and let you know how I make out.
The tractor is my wife's deceased father's. If I don't get it fixed, I maybe the same.

Thanks, again, John
Tractor is up and running and will now shut off when key is turned to off position. Just had to switch the line from the regulator (B) terminal to the other side of the terminal block