Thanks for the reply, Tedbear.

I still have my implement switch jumper, for liquid control module, on the sprayer.(in tractor's ash tray/cup holder) 

I feel, I will stick with using the Master toggle switch = I have the SC110 switchbox, located separately, in my JD4440 tractor, right above the ash tray, and it works fine verses my foot dimmer switch, which was my 2nd option. Note: I had to add a small amber LED marker light, to that foot dimmer switch, so I had a clue to whether it was Activated or Not.

Thanks for the offer, on more explanation(on alternative wiring), but I will do what is necessary, to fix or replace the master toggle switch. {Got 2nd corn spraying done, yesterday, and need to wait a little, before final soybean spraying}

Edit: I see you have already edited your reply and gave me the info, Thanks again.