Headlight wiring


Junior Member
upstate ny
On the same suburban I'm doing the boss plow on, was also wondering on how the plow headlights wire in. Like verythign else, their not a plug in anymore, have to soler them in as well, since the plugs are long gone. also have the selector switch that mounts inside the cab on the dash, with 6 posts. anyone know what goes where? thanks guys.


PlowSite.com Addict
You only asked if I knew?

OK,, I admit that was being a wisea$$. Here's the straight scoop.

It's pretty simple to wire one, and probably more reliable than all the relays and extra crap you get with a new install.

Start by locating the wire harness for the front lights. It should be running along the left fender (under the hood) and pass through the radiator support in the lower left section of it. It will contain wires for high and low beam, parking lights, turn signals and side markers. Either take out some lights and see what color the wires are or probe them with a circuit tester until you locate all the functions. DO NOT use the side marker wires as they are also flashers linked to the turn signals.

If there are ground wires on the plow lights they need to be run to the chassis somewhere. I usually look for a factory ground connection and use the same screw for the plow lights.

Splice into the turn signals and parking light wires. Run wires to their respective lights on the plow.

Then cut one of the headlight wires. Splice on a section of wire and run it into the cab and hook it to one of the center terminals on the switch. Now run a wire from the top terminal on the same side of the switch and go out to the other end of the wire you cut. This should give you both functions on your stock headlights again. May have to flip the toggle one way or the other to get them to work,

Now do the same with the other headlight wire. Cut only one at a time so you don't mess up the high/low beam.

At this point you should have stock headlights when the toggle is one way and nothing when it is the other.

Run wires off the two remaining switch terminals to the plow lights. Hook them up temporarily and verify that you have high/low beam in agreement with the indicator light.


If the headlights come off with the plow you will need to get a 6 hole trailer plug. The rectangular kind with wires coming out of the back of each half. If you're lucky you can find them with four foot leads, which make things much easier. The 6 hole plug gives you terminals for ground, high beam, low beam, both turn signals and parking lights.

Not at all hard to do, just takes a little time.


Senior Member
What boss mounting system do you have? I have the wireing diagram for the RTII mounting system. Let me know if that is what you have and we could make arangemest to fax a copy to you.
heres a question, i had both trucklights and plowlights working at the same time when i flipped the switch, now i have just truck lights no matter where the switch is, i am planning on diagnosing this tommorow but was curious if anybody had any thoughts on where to start ?


PlowSite.com Addict
I would think maybe a bad switch.

Or if this is a new install and you got the problems as you were trying to wire it up maybe this will help.

On the back of the switch,, terminals like this:

1 4

2 5

3 6

#2 = in from existing switch side of wiring, low beam

#5 = in from esixting switch side of wiring, high beam

#1 = Out to existing low beam

#4 = Out to exisitng high beam

#3 = Out to plow low beam

#6 =Out to plow high beam
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