Need some help selecting a big cutoff switch.

[That Crazy Squirrel]

I believe that is the answer. I am glad I asked the questions. Now all I have to do is locate a suitable switch and a location to install it. The other issue is the fuse. I hope to find an empty spot in the stock fuse block. That will help with the OE look I am going for.

You'll actually need two fuses, or at least one fuse and a circuit breaker. You need to fuse the lead powering the relay coil (do it before the switch), and a fuse or circuit breaker on the #2 going to the relay. You want that one as close to the battery as you can get it. I like the Bussmann brand of circuit breakers that you can find in most auto parts places.

This is what I used (I used a 150A one) in my truck to protect the wiring for the 3kw inverter I installed in the back. I mounted it under the hood, close to the battery, using self-drilling, self tapping stainless sheet metal screws (and sprayed a little undercoat on the other side of the panel where the screws came through). The cable is also strapped down to the sheet metal just before and after this, so that vibration of the cable can't loosen the terminals.

They're a little pricey, but good protection. Fully waterproof and manually resettable. Manually resettable is important, because a circuit that heavy is going to spark and arc like hell if it shorts, and if the circuit breaker is one of the "self-resetting" kind it's going to cool down, reset, short and spark again. Rinse, lather, repeat until the battery dies, something ignites and incinerates the truck, or you manage to get it disconnected. And it makes it easy to disconnect power from the winch by just tripping the test button.

 

[Lonesome7.3]

if I run all of this independent from the rest of the truck still at school system why would I need the circuit breaker?

 

[That Crazy Squirrel]

if I run all of this independent from the rest of the truck still at school system why would I need the circuit breaker?

HUH?

Not sure what that means but,,, You need the circuit breaker because in anything causes a short to ground with that 2 gauge wire you're going to have a serious problem without it. The circuit breaker, positioned close to the battery, protects the whole length of the run, including the relay, so if the cable should get damaged, wear on a sharp edge, cut, weather and have the insulation get brittle and flake off, any of the thousands of things that could cause it to short, you won't have a fire or blow up your battery/alternator.

The relay is just so you can control the power with a small switch from inside the cab, the breaker protects it all.

 

[Lonesome7.3]

I should know better than to post from my phone and not read it. I meant why do I need the circuit breaker if I run all of the winch stuff separate from the truck's electrical system.

 

[That Crazy Squirrel]

I should know better than to post from my phone and not read it. I meant why do I need the circuit breaker if I run all of the winch stuff separate from the truck's electrical system.

To keep it from going up in smoke if anything fails? And you're still using the truck's battery, aren't you?

Look, just as a "for instance", without the breaker, what happens if the hot 2 gauge cable going into the relay works loose and grounds to the frame? Without the breaker you have an instant 12v space heater. With the breaker you have a tripped breaker, and probably have to just buy a new nut and lock washer, instead of a new truck.

That's just one "for instance", there's dozens more I could come up with, but the bottom line is that it's cheap insurance in case something gets screwed up.

 

[Lonesome7.3]

That sounds like a good reason. That is why I do not want it hot at the back of the truck all the time either.