Huh?? I'll admit, you lost me. I know the plow harness is connected to both truck lights not just one and piggybacked. Its a Snowdogg MD75 plow, and their wiring schematic sucks. For $30, I'll let them figure it out.

 

So howzabout this: Feature a headlight bulb with two filaments in it, one for high beam and one for low. The are three rigid wires protruding into the envelope -- the envelope is the inside of the glass. Both filaments are tied to a common wire, and the end of each filament is tied to a dedicated wire. That way you can apply power to just one filament at a time.

The filaments don't know positive from negative. You put 12 volts or thereabouts across one of 'em, and it glows something like white hot. Preferably white hot, but not necessarily. The important part is that the wire of the filament doesn't care which way the current flows through it. So, what you've got from end to end is:

Rigid wire -- low beam filament -- rigid wire -- high beam filament -- rigid wire.

Those three rigid wires are connected to the pins in the plug.

The factory harness puts battery positive on the middle one, and switches a ground to whichever of the outer two you've selected with your switch.

The relay kit, on the other hand, puts ground on the middle one and switches battery positive to whichever of the outer two you've selected with your switch. It's *** backward to the factory wiring.

That seems the ultimate reality best choice!

 

Done yet buddy?

I think we need an updated pic of your ride with the plow yo.

 

Took it in at 1:00. Got it done They had to rewire the plow light harness. These trucks are normally switched ground (constant hot to the bulbs). The HD harness switched it around, so the plow part needed to be switched around to match.

Alls good now.

I'll se what I can do on the plow pic. Might be a week or two. It'll look stupid having a pic with the plow and no snow.