How to wire CH 4x4 switch to BD lightbar

So I’ve asked in the 3rd gen forum and haven’t gotten many answers. I am trying to wire up a CH 4x4 switch to a Baja Designs S8 lightbar. The harness that comes from the lightbar only has two wires, a positive and negative.

I want to wire up the switch so that the bottom words light up when the dash lights are on, and the top part illuminates when the lightbar is activated regardless of dash lights. I think I’ve tried all possible combinations of wiring and can’t get it to work right. I even called CH 4x4 and asked their advice. They told me wire up the switch like this:

• Red 1 and green to the positive cable
• Red 2 with an add a fuse to the tail light circuit
• And black to black

That doesn’t work. The way I have it wired up now I have:

• Green to the positive red cable
• Red 1 and black to the black cable
• And red 2 to an add a fuse to the tail light circuit

Using this, the light works when I push the switch and the bottom words illuminate with the dash lights. However, the top part never illuminates to show the bar is on, and the bottom part actually shuts off when the bar is turned on.

Is this even possible to do? All the searching I do shows 3 wires from the lightbar harness, but mine only has 2! I feel like these are common switches and the BD lightbar is very common too. I can’t imagine I’m the only guy to do this setup.

Anyone have any suggestions?

 

Wait. Do you have a relay? Because those switches top out at 3amps.

I have two of them and here is how mine work;
-Lower light works with dash lights.
-Upper light goes on when the high beams are on.
-Upper light goes off when the BD lights are on.

I know it’s not what you want but I like it that way- the switch lights tell me at a glance if the BD are ‘ready’ to go.

How I’ve got it wired;
Green is 12v from an add-a-fuse on the highbeam fuse under the hood.
Red1 goes back out the firewall to the relay, other side of the relay is grounded.

Red2 is tapped 12v from the cargo lamp switch.
Black is grounded behind the switches under the dash.

 

Yes I do have a relay. This is the harness I have from BD.

 

That harness has a switch with two wires, remove the BD switch and connect the two wires to green and red1.

Red2 and black are for illumination .

 

I just installed a 30" S8 on the weekend with a CH4x4 switch.

Depending on the size of the light bar I'm not sure you really got the right harness

From BD's website for the 30":

Please note that this light does NOT include a harness and the applicable harness to this light is 640122.

I ordered harness product number 640122. That harness has two switches, one for the main LED light and one for the Amber background lights. The main switch has three wires: Red, Yellow, and Black. The second switch has two wires that simply closes the circuit for the Amber lights.

Check out https://www.bajadesigns.com/products/s8-ir-wire-harness-w-mode-2-bar-max-325-watts.asp

This worked perfectly and was easy to work out the CH4x4 switch.

I just made a thread outlining how I installed.the switch as well but I didn't opt to include the dimmer part through for the switch so I left that wire disconnected.

https://www.tacomaworld.com/threads/sdhq-behind-the-grill-mount-bd-s8-light-bar-install.596700/

 

You sir have enlightened me. Thank you. Excellent writeup by the way. I did not order that harness. I ordered part #640115. On the BD website, if you select the 20" bar like I have, it states "Please note that this light does NOT include a harness and the applicable harness to this light is 640115." However, if you select 30" it points to the 640122 like you suggested. Upon reading the description of that harness it sounds like that is the appropriate way to go. It makes me wonder why the suggested harness is different between the two length lightbars.

The way you have your switch wired now, does it function correctly? Lower words come on with dash lights, top part illuminates when the bar is lit up? I would be willing to spend the $75 if I know this works. I have given up hope of finding a solution with my current harness, but it is driving me nuts not having it work the way I would like it to.

 

I decided not to wire in the dash light connection,that one I left disconnected, eventually I might splice it into dash light circuit but didn't have the time or the means to do it properly on the weekend. The switch otherwise works perfectly.

For the other harness that I have, it allows you to use the Amber background lights which I'm pretty sure you have .

I think the ch4x4 switch needs a 3 wire circuit. One for positive, one for ground, and one to work the relay to turn the light on and off. The 4th wire with the CH4x4 is to splice into the dash lighting to illuminate the switch at night.

Right now the lights in the switch only turno on when the light is activate (button pushed in)

 

In a two wire circuit the switch simply opens and closes the connection as far as I understand

 

Just got off the phone with BD. The tech suggested I wire Red 1 to the positive, Green to the negative, Red 2 to the add a fuse on the tail light circuit, and black to ground on the chassis. In all the combinations I tried I never tried grounding directly to the chassis, so I am hopeful that will be my solution.

 

Yeah or at least the ground to the chassis and the rest as you have tried.

 

Correct. I didn’t write down every combo I tried, but I’m sure I tried it in some capacity. Either way this will be my last try before accepting it how it is. Hopefully I’ll have some time after work Wednesday to get under there if it’s not too cold.

 

Went out to the truck last night to try the way the BD tech suggested. Still no luck. His way the top indicator light stayed on at all times and never activated the lightbar. I put it back to my original configuration where the only aspect that doesn’t work is the top light on the switch. So I’m officially writing it off and moving on to the next mod.

 

Another guy was having a similar issue on the Facebook group and it turned out he had a faulty switch

 

I'm trying to install two of these switches in my 1st gen. Do I need a relay or will an inline fuse work?