should..... be fairly simple, first you need to access the back of the switch used to turn it on, then you need to determine if it is a just a ground bump (like the tow/haul function) or it if requires voltage to activate, if it requires voltage connect a relay and toggle switch so you can turn it off when not in use or switch it back to normal mode, if it takes a ground bump you still run constant power (also with a toggle switch) and just hit the button to activate it one time and your good till you turn it off or toggle the switch back to normal.
even if this worked you may still run into to issue's where a vehicle start drops the voltage too much and it shuts off anyway