After a cold weather no-start when no 120v was available for the block heater I decided I wanted another way to fire the truck under the same circumstances. Also wanted a way to lock out the grids when I so desired, here’s my two part solution.
Wiring consists of a switch, momentary push button and pilot indicators in the cab for the grids. I wired this so that the dpdt switch acts as an interlock system for the grids when either start is used.
Flip the switch one way – no grids and either enabled through push button.
Flip switch other way – either start locked out and the grids are functional.
The two pilots are wired to the load side of the grid relays, kinda fun to watch.
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Wiring consists of a switch, momentary push button and pilot indicators in the cab for the grids. I wired this so that the dpdt switch acts as an interlock system for the grids when either start is used.
Flip the switch one way – no grids and either enabled through push button.
Flip switch other way – either start locked out and the grids are functional.
The two pilots are wired to the load side of the grid relays, kinda fun to watch.

