Ford 640 Wiring Harness

I purchased a wiring harness for my Ford 640. My tractor has been convered to 12 VOLTS and the wires were taken off before we got the harness. There were no labels with the new harness as to which wires go where. The diagrams from K. LaRue is not consistent with the color coding on the harness so we can't follow that. Can someone who has a 640 12Volt layout the wiring for me please?
 
Current going through the wire doesn't care about the color of the outside of the wire.

Take your new harness and the diagram you have. note the wires in the diagram and find the wire in the harness that will match that function. For starters the heaviest wire should be the charge wire from charge source (generator/regulator/alternator) to Ammeter if present, then to starter solenoid.

You may have to modify some of the wires in the new harness
 
(quoted from post at 07:03:55 05/22/20) Current going through the wire doesn't care about the color of the outside of the wire.

Take your new harness and the diagram you have. note the wires in the diagram and find the wire in the harness that will match that function. For starters the heaviest wire should be the charge wire from charge source (generator/regulator/alternator) to Ammeter if present, then to starter solenoid.

You may have to modify some of the wires in the new harness

Are you saying haviest wire meaning guage or thickness of wire.
 
(quoted from post at 07:03:55 05/22/20) Current going through the wire doesn't care about the color of the outside of the wire.

Take your new harness and the diagram you have. note the wires in the diagram and find the wire in the harness that will match that function. For starters the heaviest wire should be the charge wire from charge source (generator/regulator/alternator) to Ammeter if present, then to starter solenoid.

You may have to modify some of the wires in the new harness

The previous owner took the old harness off when he updated it to 12 volt.
 
The previous owner took the old harness off when he updated it to 12 volt.

Then he really didn't convert it to 12 volts as much as he simply installed 12 volt components without getting anything working. A conversion implies that it starts, runs and charges properly, all using 12 volt components. What compnents are 12 volts now, just the battery? Or is there a proper 12 volt alternator as well? What about the headlights and tail light(s)?
 
You asked, "Are you saying haviest wire meaning guage or thickness of wire." Yes. A heavier or larger (smaller number) gauge is going to be thicker.
 
(quoted from post at 09:37:10 05/22/20)
The previous owner took the old harness off when he updated it to 12 volt.

Then he really didn't convert it to 12 volts as much as he simply installed 12 volt components without getting anything working. A conversion implies that it starts, runs and charges properly, all using 12 volt components. What compnents are 12 volts now, just the battery? Or is there a proper 12 volt alternator as well? What about the headlights and tail light(s)?


Everything is 12 volt now except the ampmeter. I connected all the wire by the diagram and now, when I connect the positive battary cable the tractor starts on it own. The key nor the push bottom is working. What did I do wrong. As soon as I touch the positive cable to the battary it starts.
 
Everything is 12 volt now except the ampmeter.

The ampmeter doesn't care about volts it measures the current in amps and should work in a 6 volt or 12 volt system.

when I connect the positive battary cable the tractor starts on it own. The key nor the push bottom is working. What did I do wrong.

It's possible that you did nothing wrong other than believe that the previous owner installed the correct type of solenoid for that tractor. Your symptoms definitely seem like it is an automotive style solenoid that has one side of the primary grounded to the case and engages whenever power is applied.
 

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