DIY: Wire a 4 wire led light bar switch to a 2 wire led bar

Here’s a quick write up on how to wire up a 4 wire LED light bar switch (mic tuning) to a light bar with only 2 wires (typically a red (+) and black (-) wire). You don’t need much experience to do this. (Almost) everything can be done right there at the driver side kick plate utilizing the mini-fuse block, factory ground and stealing power from an adjacent button to get the text backlit, so when you flip your lights on, the text on the button comes on too, like out of the factory...you only need to run 1 single wire to your led light bar (out the firewall, along the fender and to your light bar).

Switch:MICTUNING [New] LED Push Button Switch with Connector Wire Kit for Toyota - White Laser Etched LED LIGHT BAR Symbol

MICTUNING Backlit LED Light BAR Symbol Push Button with Wiring Kit ON-Off Switch Replacement for Toyota (White, Surface Size 1.28 x 0.87"es

https://www.amazon.com/dp/B01G1W7YZ4/ref=cm_sw_r_cp_apip_lB8ZslveSaIMO

The switch come with 4 wires from left to right:

Black: Ground this wire (there’s a factory ground right there behind the panel next to parking brake) I added a foot of extra black wire (solder together) and a U connector. Unscrew factory ground, insert U, tighten. Done.

Red wire (immediately next to black): This is power for the text on the button “led light bar”. You want to steal power from a button next to your new button that comes on when you turn your headlights on. I chose to use the tiny yellow wire going into the bed cargo lamp (on/off) light. I attached a “t-tap” wire connector which allows you to tap into the tiny yellow wire without cutting.

There’s a space; then another.....

Red Wire: This is your “trigger wire” and powers your relay. In my pics I have mine attached to a mini led light to confirm working order. In reality I soldered about 8 feet of extra red wire to the end of the wire and passed thru the firewall just above the brake pedal and into engine bay. This would then go to the red wire (trigger) of your relay. Using an inline fuse along this run is highly recommended.

Green wire: use an add-a-fuse and tap into something like the 15A “rear prk light fuse”. This provides the power to your trigger. I added about a foot of wire to the green wire and then added an add-a-fuse. I then plugged my add-a-fuse into fuse. Done.

You do need to ground the black wire coming from your new led light bar. Ground this somewhere close. I’d go with a factory ground in engine bay. You DO NOT need to run this ground all the way back inside the cab to the ground point of the switch. Waste of time and wire.

If done correctly, the button will not do anything when the truck is started.

1. Turn on headlight; new led button text should light up. The led picture above should not.

2. Press new button in, the led light bar picture should light up (along with text below). Led light bar should turn on.

3. Turn off headlight; just led light bar picture should be lit. Text should not be lit. Led light bar should be on.

4. Turn everything off...everything should go off...crack beer, drink beer, repeat.

Link to add-a-fuse: you need the LOW PROFILE MINI FUSES like these if you follow my lead and tap into the fuse box by the parking brake. These will not work for the engine fuses, they are too small. There are 3 sizes of add-a-fuse, these are the ones for the driver side fuse panel. LOW PROFILE MINI...
ABN Fuse Tap Fuse Holder & Fuse 5-Pack - 12V Add a Circuit Kit - ATM Low Profile Mini Fuse Blade & 15A AMP Adapter

ABN Fuse Tap Holder & 5-Pack - 12V Add a Circuit Kit - ATM Low Profile Mini Blade & 15A AMP Adapter

https://www.amazon.com/dp/B01BU59QA8/ref=cm_sw_r_cp_apip_o19CFll54W8jS

 

Thanks, I wasn’t really thinking of the guys using nice, powerful stuff,. I’m gonna be getting a 100w or so 23” as not much can be done with these 2nd gens that I can find...

 

+1, I have that switch and a relay for each bar. No way that switch is going to handle a light bar.

 

I appreciate the heads up. I intended this more to be about breaking down the 4 wires to 2 and which wire to use to steal power for the headlight operated part, I couldn’t find anything for 2nd gens myself. I’m glad I’m learning something as I’ve yet to buy a light bar, just did the wiring today. Are you saying, no matter which light bar I go with, even a 23” 100w $150 one, that a relay must be used? There’s a good video of a dude hooking up this switch to his tundra led bar on YouTube, although he goes from 4 wires to 3 wires, Caliraised I believe. He mentions no relay or switch and Caliraised even liked the video and commented “good job”. Not arguing, just surprised...

 

With that switch, yes. Your light bar will pull 8 amps which isn't a lot but it's more than the switch is rated for.

Your wiring is spot on just you'll just move that red wire to a relay. On the relay you'll have pin 30 that goes to the battery with a fuse. 85 will go to ground, 86 is where your red wire will go, and 87 will go to the light bar.

 

Can any of you guys link a good relay you’d recommend? Ty

 

What he said. Something like this is nice since it includes the wiring pigtail.

$10 irhapsody 1 Pack 40/30 AMP 12V DC Waterproof Relay and Harness - Heavy Duty 12 AWG Tinned Copper Wires, 5-PIN SPDT Automotive Relay

https://www.amazon.com/PACK-AMP-Wat...=bosch+relay&qid=1564417544&s=gateway&sr=8-14

 

Guess I’ll be doing more wiring. Thanks for helping me not burn my truck to the ground guys.

 

Good stuff, thanks.

 

bare with me as I’m new to relays and my mind has just been blown away watching a video about them. One question, what can I eventually do with the #87a pin (that’s isnt being used for this application) can I use that as a trigger wire or to power another item, like additional light bar? Just curious...

 

You could but it would be powered all the time. Only time I've ever used one was for adding a set of lights on a snow plow.