How to wire a harness?

I recently bought a 20" led bar and it came with a wiring harness with this switch... I'm hoping to wire this harness to an oem toyota center console switch for fog lights but I have no clue how to go from the 3 pin/wires on this switch to converting to the 4 wires on the oem. Help pleasee

 

And this is what in going to be hooking it up to... How am I supposed to go from a 3 pin illuminted switch to a 4 pin illumintated switch?

 

I believe the wire you are missing from the harness switch is the parking/headlight tap since your harness switch doesn't illuminate. You'll have to find another wire under dash to illuminate the switch.
I also just got a OEM type push button switch and going to replace the switch on my harness.
edit: My old switch only has 3 wires too.

 

Well, the switch I have now, has 3 wires and it does illuminate. And the oem has 4 wires. And it also illuminates soo how do I go about wiring it

 

Ok i just did mine. I was mistaken, my old one has 3 wires new one has 4. I hooked up the red wire(power out) to #85(blue wire), black wire(ground) to black wire(#86) and green wire(power in) to white wire(30). I still have the blue wire unconnected. The switch and light bar works fine its just that the "LED LIGHT SWITCH " isnt illuminated when the dash lights are on. But the light bar(on the switch) does light up when you push it on. I'm going to tap the blue wire into the same wire on the fog light switch right next to it and should be good. If you have a meter its easiest to cut the old switch off and strip an inch of wire off the ends and just test the 3 wires. One wire should have 12V and thats the power coming in (mine was white 30). Look at your relay and see which wire is going to ground(mine was black #86) and thats your ground wire. Then connect the other wire(power out) . Then your switch and bar will work fine but you just have to find a wire in dash to tap into for switch illumination. My switch is an AOB so my switch wire colors are different but you get the idea.

 

Soo what is the function of each of these wires(blue,black, white) and what would they connect to on the switch

 

It may be different colored wires on your harness but i explained int on my last post. On mine it was blue=power out, black=ground, white= power in. Your switch is different then mine. Should have come with some type of instructions saying what each wire goes to.
Looks like tome on yours it would be #2=black, #3=white, #4=blue

 

For the switch illumination, pull +12v from one of the dash lights. That way it'll be off during the daytime and on with the rest of your dash lights. Otherwise, if you pull the +12v from somewhere else you may have the switch constantly illuminated or when you don't want it to be.

 

Just the Thread I needed! I had the same issue as the OP. Electrical work is not my specialty.