I have recently purchased an older Freightliner FLD120 and I am setting it up to pull my Sundowner LQ. Everything has been going great up until I tried to wire the plug for the trailer. There is an existing plug and wire on the truck. It looked simple enough to me until I got out the tester. The problem is that the brake lights and the blinkers are on separate wires. What is the simple procedure to make the existing harness work for my trailer? The following is the list of the wires I diagnosed with the tester.

Red-Brake Lights

Yellow-Left Blinker

Green-Right Blinker

Brown-Lights

White-Ground?

Black-Lights

Blue-Trailer Brakes?

The simplest way is to wire your trailer plug off of the tractor's tail lights, NOT off of the existing trailer plug. The tractor itself is the same as your trailer- combination brake light/turn signal on each side in the rear. Just wire your new plug off the apprpriate wires at or near the tail lights themselves. I make a lot of semi tractors into haulers, and this is the simplest way to do it. If you need to, give me a call- I can probably explain it better on the phone than I can type it! (800)798-9813

Bill  

Thanks Windy,

I was hoping to use the existing harness but I can definitely tap into the Tractor's tail lights. You may regret giving me your number because I am sure I will come up with a ton of questions before I am done.

Thanks again

I got it all wired up. I had heard about the adapters but was going to look into that as a last resort.

I used the wiring from the Truck's lamps for the stop and turn lights. I used the ground and the running light wiring from the existing trailer harness. Worked out great and my interrupt switch still works for the tail lights. Thanks for the help and Bill it was good talking to you.