I put an 09 bed on my 06 f150. It fits great, except the tail lights are different. The 06 has 2 bulbs, the 09 has 3. I ordered the wiring harness for an 09 that has the 3 bulb plugs, 2 license plate and the square connector!! The 06 is a round connector. I couldn’t find a square connector so I’ve decided to cut that off the new harness and wire in the round 06 connector. My problem is that I can’t find a wiring diagram that will help me!! 06 wires are different colors from the 09 harness!! Any help would be greatly appreciated thanks!!

09

09

06

06

 

If we can't use the plugs, we just cut them off.

What you might consider,,,,,,,,,,,,,,,, go to a good auto supply store and purchase around 12 heat shrink butt connectors ,,,,and a test light.

Now when you turn on the parking lamps you will know which color wire is for tail lamps.
Then turn them off, key on turn on left signal and make a note which color wire that is,,, then do same with right signal. If turn and stop lamps use the same element in the bulb all you need to do now is strip off about a 1/4 inch of insulation of all wires that had plugs and you are ready to connect some wires.
When you turn the parking lamp sw on , you can touch that wire to the wires going to the left rear tail light wiring. One will light brighter than the other. The dimmer light is for the parking lamp and the bright lit element is for signal /stop lamp you can do this with all the different wires and once you know which work which, you now can crimp the wires in the butt connector and you now have a good connection. When you finish each connection , you can use a heat gun or lighter to heat the shrink material on the butt connector to make a solid weatherproof connection. Pretty sure you can figure out the best way to do all the wires and now all you need to do is secure the wiring so it doesn't dangle around and looks neat and you are done. If you don't have a wire crimping tool, you might get away with using a pair of vise grip pliers , but you must be careful to only crimp one end at a time. This all may sound a little complicated at first, but you can do it, just take your time.
I forgot to mention , one of the wires coming to the rear will be a ground wire, just another wire to connect.

If you require any addl assistance, let us know.