Cabin Fuse Box - 7.5A Tail for powering BD S8 Backlight

I did not use a jumper wire but I tried testing by hooking the (amber) red wire to the green switch wire. Same result, both lights turned on.

I also tried the previous configuration of the (green) backlight wire to the blue switch wire and that did not work either, so that’s why I ruled the switch to be faulty.

 

Since you suspect that the switch is bad, you could open it up to view the board for brown/black/burnt evidence...

 

You should get a different switch than the one you have. One that selects White OR Amber (like the original switch), that way you prevent sending juice to both white and amber at same time.

 

“I wired the new configuration based on this:
coupled 12V black ground —> black ground switch”

Keep the switch dimmer circuit completely separate from your light bar harness, especially the grounds. The dimmer circuit is not the same ground. That means don’t connect the black switch wire to any other wires if you connect it to the green dash illumination wire. You could lend up with positive voltage on both sides of a relay coil rendering it inoperative, or short out the illumination circuit if you also connected them to the chassis.

 

I’ll look at this option instead. Since it’s unlikely I would have both bars on at the same time.

 

WTF?

 

The LED bars have 2 relays each?

 

Think about it, he says he connected the blacks together. If it’s also connected to the green jumper wire that puts a positive voltage there. If he doesn’t and connects to nothing else it’s not grounded. If he does and also grounds to the chassis it’s a dead short of the green wire in the illumination circuit.

 

Well, 1 relay for each led bar harness.

 

If he has, then yes. He does it correctly then the don't place the switch ground to the vehicle illumination is an incorrect statemant:

 

Aw shit, how does one relay change the amber to white on your TACO, or do you have the amber on a separate circuit?

 

I am not sure, but again I suspect the actuation of the white switch also switches on the amber relay.

Technically the amber is on the same circuit, as it’s coupled on both the ground and 12V source.

 

Do you have the DD site link to the Bars you have? Or have clear picture of the relay wires to the bars?

 

Obviously. What I said was don’t connect the illumination ground into the relay ground. It’s for the switch alone and nothing else.

 

Light bars: https://www.bajadesigns.com/products/s8-straight-led-light-bar/

Harness: https://www.bajadesigns.com/product...ch-1-bar-wiring-harness-universal/?sku=640122

 

Harness linked shows separate switch for backlight feature.

 

It does, but there's no info on if white color has priority over amber.
As in:

• Vehicle OFF, all OFF
• Vehicle ON, Both switches left ON, White illuminates only.
• Vehicle On, Amber selected, then white is selected and amber is off, even with amber switch on.
• etc...

 

Backlight is wired independently at the moment, tapped to tail fuse and works as intended.

 

Does it turn OFF if you select white LED's? The amber switch looks high amp type, not 3 amp max type. (like the Dual China switch giving you issues)