I am about to install a light bar on my front bumper. I previously installed two LED pods on my rear bumper and I taped the power wire to the backup lights and put that into the 87 position on the relay I installed so the new lights only come on when I am in reverse. I want to do the same thing up front where the new lights only come on with the high beams. My problem is I cannot figure out which is the correct wire to tap. I pulled a front Headlight yesterday and used my volt meter trying to determine which of the 3 wires was my high beam but one side was always hot and the other side seemed backward like it would be on with the low beams and shut off when you went high beam. The middle is the ground on the 9004. Has anyone done this that can tell me where to tap? I have the single-bulb version that is both low and high. I feel like if I had the double bulb version like on the sport this would be easier. Any advice about how to do this would be much appreciated.

 

You might want to setup your light bar on a separate switch, as wiring it to come on with the high beams will likely be illegal in most states. At a minimum, you should also consider running those lights through a relay and a separate switch, as the headlight switch and wiring is already overtaxed just running the OEM headlights and is known to go bad just with the factory headlights.

 

I am doing both of those things. It will be run through a relay and a 3-position switch. All I am taping the high beam wire for is to energize the relay so that when the switch is in a down position I can then hit the high beams and the extra lights will work with them. And its not illegal on the high beam switch it is illegal if you have them on all the time. My entire goal is not to be an A HOLE and blind people. If they are hooked up to work with my high beams then when oncoming traffic is coming of course I would turn them off as we always should I just don't want to have to work two switches in that scenario. Here is a video of exactly what I want to do except I don't want to tap the fuse I want to tap the wire at the headlight. I think I found it today.

 

Thanks for the clarifications about not running the light bar all the time on high beam. Not sure which wire it is for the high beam, but it should be easy enough to find with a test light at the headlights (and checking the 3 wires at the bulb) with the high beams turned on.

 

Yeah, I did that today and I think I found it the only curious thing ( i am no 12-volt electrical expert so this might be normal and I just don't know that) is that the volts came up with a negative symbol. I found a drawing telling me the location of the ground, low beam, and high beam locations in a 9004 plug. So I put my positive lead from my meter in the high beam socket and the negative lead in the ground socket and had my kid turn the high beams on. Sure enough, I got a reading when on HB and zero when off but the reading had a negative symbol which I don't understand.

 

Negative reading comes from multimeter leads being backwards (neat way to find a polarity from the cables if you don't have wiring diagram).
But if you connect a normal relay coil to hi-beam wires, it really doesn't matter which way you connect it, coil doesn't care about polarity. Unles there's a diode inside the relay, then 85 is ground and 86 positive (but I connect relays that way regardless there being diode or not).

 

I don't understand why people even use light bars, Wheeling at night is about the only use. A light bar is not going to project light like the high beams. And if you want the fogs on there is a sticky i believe on how to do that. Upgrading both the headlights and fogs is the way to go. Modern day projectors!

 

I don't know what kind of light bars are used in US, but here in Europe they are quite popular, and they are specifially built to light the road far ahead.
I've installed quite few of them, and have one on my Ram.