is it possible to wire an add a fuse to a switch so it can be turned on and off? When selecting a place to put the add a fuse its always in a position thats on when key is on but I need to have it wired to a switch

installing a light bar/strobes/etc in my honda - for firefighter use

 

What year and model is your Honda? 94

 

93 civic hatch

 

I think I actually figured it out on my own.. wire the power wire to the switch, then send the + wire on the accessory im wiring to the back of the switch and the negative wire on the accessory gets grounded

 

It depends on the what the "load", [current draw] is, or how much power the accessory uses, things like lights and strobes use a lot of power, [current] so it is always best to draw that power directly off the batt. using a relay and use the switch to control the relay.

Using a standard automotive SPDT ot SPST relay... http://www.the12volt.com/relays/relays.asp connect the load, [lights] to #87 of relay run a fused lead from batt. to #30 of relay, ground #85 of relay and connect the output of a switch to #86 of the relay, the input to the switch can come from one of the free pins on the under dash fuse box, the free pins are used to add power accessories to your car, you will find free pins that are constant power, [hot at all times] 2nd ign. free pin, [hot only when ign. switch is in run] illumination free pin, [hot only when park/head lights are on].

If the load, [accessories current draw] is low a relay is not needed and the power for the accessory can come directly from the free pins, [through a switch]. 94

 

I wired one of those light bars into my brother in laws pontiac. I can tell you for a fact that they pull way too many amps to plug into an accesory fuse under the dash. They have to be run directly to the battery.

His control box had all the relays built into it though, so there were no extra relays to worry about.

IIRC it was just big wires to battery and ground, and another bunch of 12gauge wires run to the switches

Post a pic and some info on what you have and we can advise you on the best route to take