I am setting up a relay panel for the car to control things like the fuel pump, water pump, fans, etc. I will use ground switching as much as possible since it is safer than voltage switching.

I think I can use the ECU to control the pump and I think I can create a digital switch on the digital dash so I can turn the pump on even if the engine isn't running. Might take me a while to figure it all out though. Lots of new stuff to learn.........