High Amperage Light Bar Wired Into Up-Fitter Switch (DIY Custom Harness)

[rdsc]

Alright so I ran into an issue trying to install a Baja Designs OnX6 Light Bar recently. The biggest amperage switch on the GEN2's is 15 amps. My light bar is 21 amps. So after some research, and a whole lotta help from 4x4TruckLEDs.com (Seriously this gent helped me put this altogether and I didn't even get the light from him, amazing customer service! He's got a customer in me now.)

So, here’s the deal. For those of you that don't know you can still run a higher amperage light via the up-fitter switches, you just have to install a relay in between. Essentially the up-fitter switch powers the relay, and the relay powers the light.

The Baja Designs OnX6 Light Bar also has a mode selection feature. High, Low, and Strobe. To utilize this feature I installed a second relay and tied this relay into my 6th Up-fitter switch. So with the light on (Aux #1) I can then toggle my Aux #6 switch to control the mode selection. If I toggle it twice (ON then OFF) the light switches to Low Beam, toggle twice again (ON then OFF) back to High Beam. If I toggle it three times (ON then OFF then ON) it switches to the Strobe function...

Pretty cool right?

Here's what you need...

1. (2) 40/30 AMP - 12 Volt Relay's (Assuming Your Light Bar is Under 30 AMPS)
2. 12 Gauge In-Line Fuse Holder
3. 25 AMP Fuse (Again Dependant on Your Light Bar's AMPS)
4. 4 Feet of 12 Gauge Wire
5. Various Crimp Connection Ends
6. Various Sizes of Heat Shrink
7. Zip Ties

That's pretty much it, install time for me took about 2 hours. But I took my time, I drew out my diagram on a white board and triple-checked all my connections. I used heat shrink to seal up all my connection points as well.

Diagram pictures attached below. Hopefully this helps others.

Cheers,

 

[4x4TruckLEDs.com]

And the student becomes the teacher

 

[DJRappy]

Awesome! Great work and nice explanation.

 

[rdsc]

And the student becomes the teacher

LOL, just trying to pay it forward...

 

[cfwilk]

RDSC - had to say thanks and that's an understatement. I have a 40" BD OnX6 Arc Racer and several other pairs of squadrons and 10" as well as a 20" Rigid all for front and back ADD Honeybadger bumper. Anyway - after getting NO harnesses with lights because I didn't know BD did that (Rigid which I have several of on my Jeep supplies harnesses), I spent 20 min on phone with BD and spent another $232 for harnesses for 7 BD lights including the 40". Then spent many hours on and off for clear and knowledgeable advice on connecting to my 2018 Rator up fitter switches - AMAZINGLY BAD info out there! Until I found YOUR post - dude thanks - I bought the relays and in-line fuse, - had wire and clips, etc. - my 40" working perfectly on Switch 1 for On/Off and Switch 6 for Dim/Strobe. I can't say thanks enough.

 

[sp2pilot]

@rdsc,
So did you remove the weatherpack connector off of the lightbar and put new single ones on for the white and green wires?
I just received my onx6+ lightbar, with two harnesses(neither have green wire) and a confusing set of directions.

If one didn't want to utilize the hi/low/strobe function, that wire coming out of the light bar can just be taped up?

 

[8WOOD]

Good write up. Quick question? Couldn't you just change out the relay and cirutbreaker feeding the up fitter from the battery... such as put a 40amp and not have to have one in your wire?

 

[4x4TruckLEDs.com]

Good write up. Quick question? Couldn't you just change out the relay and cirutbreaker feeding the up fitter from the battery... such as put a 40amp and not have to have one in your wire?

Technically yes... but you run the risk of the wire melting before the fuse pops. Your fuses are rated for 2 things...

1) The amperage your device requires
2) The gauge of the wire

So if the wire is a thin 22 gauge you cannot put a 40amp fuse on it... you'll melt the wire first before the fuse pops.

So you SHOULD NOT just change the fuses out on the upfitters.

 

[8WOOD]

Thanks 4x4LEDS. Electricity is dark magic and I dont understand it. Guess I'll be following this guide for my onx6+.

 

[4x4TruckLEDs.com]

Think of it like plumbing... where amperage is your water pressure and gauge is the size of the pipe.

If you have 100PSI of water pressure that goes through a 1" pipe without issues you can think of the 100PSI as say a 40amp circuit and the 1" pipe is equivalent to say a 10AWG wire (the smaller the AWG the thicker the wire).

Now if you take that 100PSI/40Amp circuit and try and push it through a 1/8" pipe now (call it a 22AWG wire) what do you think will happen? BOOM right? Same idea here... only your pipes/wire is gonna blow up before the pump knows to turn off (aka, the fuse blowing).