Need help with light switch wiring

Hey all,

Totally newbie problem that I'm throwing out to the TW lighting pros. So I just installed a 32" light bar in the lower front bumper today. Was a cheap ebay bar that came with a harness. Overall the install was a success and everything went smoothly. I wanted to keep an OEM appearance so also bought an oem style switch to mount in the dash and replace the one that came pre-installed in the harness. However, the connectors for the oem switch and the ones that the bar came with look very different. The oem switch has 4 wires (red, green, black, blue) while the original switch has 3 wires (white, blue, black). Can someone point me in the right direction as to how to make this work? I'm a complete idiot when it comes to anything electrical.

Here's the switch that came with the light bar...


And here's the switch I'm trying to replace it with...


There is also an intermediate connector between the original switch that came with the light bar, and the rest of the harness. I assume they did this to make it easier to route through the firewall...


And here's a pic of the almost finished install for kicks...

 

Did the OEM-style switch come with a wiring diagram? It looks like an air onboard switch so I'm going off the diagram here:

https://www.tacomaworld.com/threads/oem-to-air-on-board-fog-light-switch-wiring.369623/

I would say that the wiring goes something like this:

Red/Yellow => Middle wire
Black => Black wire
Green/Yellow => Whatever wire is left from the generic switch
Blue wire => Dash illumination (can tap into the in-dash fuse box or stock radio harness)


Depending on how much room is available behind your switch location, you might crimp on some quick disconnects to the OEM switch to avoid having to solder anything.

 

Thanks for the info Chenbro! I'll try that configuration. Also, forgot to mention that the generic switch has an LED which only illuminates when it's in the ON position. So does that mean I don't have to tap into another power wire to get dash illumination on the OEM switch? And can I bypass dealing with the blue wire? Or is the OEM switch just built differently and requires to tap into another wire for illumination? Guess I'm just trying to wrap my head around how the generic switch manages to handle power, relay, ground, and illumination with only 3 wires

 

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Post where you got the switch from. This is very simple to do but we need to know the correct pin out of the OEM style switch. We don't want to steer you wrong.

 

The OEM switch probably has two wires that are for the pos and negative illumination so it'll dim with your dimming controls. The other two wires will the 12v in and out that goes to relay. I'm not sure which colors are which though.

 

Can you trace the white and blue wire back to the relay? Pull the relay off the harness and tell me which wire goes to what number pin. You should see the numbers next to the terminals.... Hopefully.

 

Got the switch from eBay. Looks like this one...
http://www.ebay.com/itm/261785192261?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

I couldn't see exactly where the white and blue wire go back to the relay as it's joined with a plug and completely wrapped in insulation. I didn't want to cut through it if avoidable. But pulling the harness off the relay exposed the numbers on the terminals...

 

Green/Yellow => White wire - although you should use a switched 12volt source - this will prevent leaving the light bar on when truck is completely off.
Red/Yellow => Blue wire - triggers relay
Black => Black wire - ground

Blue/yellow wire - Dash illumination - use an "Mini add-a-circuit" and tap into the in-dash fuse box "tail" fuse.

 

Do you have a voltage meter?

 

You, sir, are a Godsend. I'm going to the parts store tonight to get some quick connects and bits to make this happen. I do not have a voltage meter. Is this something I need? I wouldn't even know what to look for with it lol. As for the blue/yellow dash illumination. Can you point me to a link or source where I might find an add-a-circuit? Also, where is the in-dash fuse box located? Thank you!

 

that can be found at most parts stores... make sure it's for the mini fuse. if they have a low-profile version of the mini - get that one.

 

OK, got everything wired up just like fergyz outlined. Worked like a charm! Thanks again for everyone's help. Couldn't have done this alone and probably would have a made an epic mess of things haha.

Started by taking off some panels to access the in-dash fuse and remove the blank switch


Popped in the OEM style switch and wired as per fergyz instructions


Inserted the mini add-a-circuit into the #3 tail fuse behind the dash


Secured wiring and reinstalled panels


Let there be light!

 

Where did you run the wires through the firewall? I am trying to find the best place without using the drain plug above the frame

 

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Did everything on here correctly. However, the switch itself is always on, even if the car is off. And the dimmer won't work. Any ideas.

 

As it should be if these particular instructions were followed. The above setup means an always live switch and no dimming with factory dimmer. You'd need a switched 12v source for power if you want the switch to only work with the ignition on.