Dave always has the most entertaining build threads!
I wouldn't us an 80-amp solenoid (and fuse) to jump start, or run a winch.As for the scenario of helping your dead starter battery, you could always run another 12g "ON" wire from the + on your rear battery to the 80A Solenoid, but put a switch in the cab so you could enable it only when needed, this way, while sitting in your seat, you could flip the switch, and connect the batteries to start your truck!
Wouldn't get a charge from the alternator if the engine was running but the switch was off.ok so say i hook the keyed power to a toggle switch, and have it off most the time. would that just mean the house battery wouldn't get a charge?
The batteries would equalize. If the house battery was low and the engine battery was high, then the house would rise and the engine would drop until they were equal.and what would happen if say the switch is left on while the vehicle was not running, would it just drain the start battery?
Absolutely. Just jumper from the input of the first solenoid to the input of the second solenoid and the same with the wire to energize them. They'll draw something like an amp each so you probably won't even need a larger fuse to power them.Could you run 2 of these circuits (2 sets of fuses and 2 relays)
The fastest way to figure out where to run your wire to the fuse box is a 12V detector thingamajig. Turn your key to 'ON' (don't start truck) and then start probing empty holes in her fusebox. At some point your thingamajig will light up. Write down all her locations that lit up your thingamajig and turn her OFF. Then start probing those same empty holes in her fusebox that lit up your thingamajig again. Find any empty hole in her fusebox that lit up your thingamajig when she was turned ON but got no light from your thingamajig when she was turned OFF - that's the circuit you want to use (ALL THE TIME, if you get what I'm sayin )How can you determine where to run to the fuse box? Would this be on a wiring Diagram to show what is hot and what is not?