Insert a Toggle Switch

Think of the hot wire going to your assesorie deviceand cut wire in half and your switch will have 2 terminals. Put each end of cut wire, one on each of the terminals . When you flip the switch one way it will make the connection on the two wires in the other position it will break the connection (off)

 

Don't go getting it to the ground thing, this is 6th grade science!!!!

This has nothing to do with a grounds, get a simple on/off toggle at any major truckstop, put blade (like pictured) on end of length of wire about 4-5" long, use butt connector on other end to connect simple in-line fuse holder, take butt connector and connect to other side of in line fuse, add length of wire to get you to where you want toggle mounted, use correct connector to hook to one side of toggle( this depends on toggle you find), take another connector hook to other side of toggle with a length of wire to get you back to fuse panel, add blade connector (like pictured above) to end of that wire, now you can plug both blade connectors into fuse location, does not matter which side. The inline fuse still protects you and the circuit if there ever was a short.

 

What size is the fuze your replacing?

 

Gonna be hard to find something to fit in those small mini's but they are out there. If you can't find anything you can get what are called "fuse taps", they fit around the the metal tabs if the mini's and allow you to tap into its power, you can get those and replace the mini with a blown mini and continue the install. That's last resort though if Nothing else works out for you.

 

Can we back this up, I think you may be making this way harder than it actually is. What exactly are you wanting to wire up? There may be a much simpler way.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=071-580

You can have key off fuse hot
You can have key off fuse off
You can have key on/ignition on fuse hot
You can have key on/ignition off fuse hot

 

on one hand. there is usually some terminals in the fuse box that are hot at all times. and some that are hot with the key.

on the other hand. the mechanics i have talked to lately all say that trucks are NEGATIVELY hot. and POSITIVELY grounded now.

so, before you go screwing around with your truck. you might want to make sure it's positive hot and not negative hot.

i have an o5 w9 and i keep getting told it's negative hot.

 

Google is your friend
http://www.offroaders.com/tech/12-volt-wire-gauge-amps.htm
For a 15amp your looking at an 18 gauge for anything under 5 feet. 14 for up to 20 feet and 12 for 25 feet.

So what you will need is:
18 guage wire (2-3 feet of it)
a two postion toggle switch.
an inline 15 amp fuse.
Two female connecters to connect to the toggle switch. 18 guage (but make sure they fit the toggle switch)
Two male connecters to connect to the fuse box. 18 guage, but make sure they have the small heads on them so they can plug into the fuse box).
One butt connectors, to connect the inline fuse to a wire.
Heat shrink tubing (this is optional, but I believe its good to take the xtra step)

On the positive side of the fuse box connect one of the male connecters into that half of the fuse slot. With one side of the inline fuse wire going to it. On the other side of the inline fuse use the butt connecter to connect a desired length of wire. On the end of this wire use a female connector to connect to the toggle switch. Take anouther length of wire, and put a female connector on it and plug it into the other blade on the toggle switch. runing the wire to the fuse box. Place the last male connector on the end of this wire and plug it into the same fuse slot as the first one you pluged in but this time on the negative side.

What this setup will do is with the toggle switch in the on position it will act just like it is now. All power will be run threw the fuse box, and it will still have a fuse installed preventing overload. When you turn the toggle switch to the off position it will seperate the connection, effectivly turning all power off to the device you want off.

Here is a picture of how it would connect to the battery box. Well sort of as this picture is just feeding off the positive side. But it does show the inline fuse and how it is pluged into the fuse box. You would acualy have two wires going to the fuse box. One in each slot.