Looking at the bed switch that's not a momentary switch, that is an SPST on/off switch just like a light switch in your house. You could mount a hood switch from a gen 12 truck like mine that's normally open with gate closed and when you open the gate it closes contacts until the gate is closed again. Wire it in parallel to that bed switch. It is a ground switching circuit and the power is fed by the microchip in the BCM.

Doing it that way you would retain all OEM controls.

 

Cool, thanks be unto you, helped me out again!

 

Anytime.