Help! The flat four and seven round electrical plug-ins on my 2002 Supercrew are not working right. On both the left turn signal, headlight, and brake light dont work. The right turn, head, and brake lights do work on both. First thought was a loose wire, but why would it not be working on both plug-ins?

Also, does anyone know which color wire does what?

 

Check the fuses. sounds simple but you never know. I did the same thing with my old truck and there was two fuses and just one was blown. New one and wow it worked. Just a quick check, worth a try.

 

Standard Color codes at 7 pin round connector:
Ford uses some different colors. one is orange but go by pin function when testing. Look on the weather cap for physical relationship to function.
1 = common gnd- white.
2 = electric brake- blue.
3 = tail lite/ lic- green.
4 = battery charge- black.
5 = left stop & turn- red.
6 = right turn & stop- brown.
7 = center aux - yellow.

4 pin connector:
1 (exposed on the bottom) = ground - white.
2 = tail/lic/markers - brown.
3 = left turn/stop - yellow.
4 = right turn/stop- green.

This info is from page B31 of tech section, Tekonsha and my 02 factory cabling that is functioning for towing.
See your owners manuel pages 206 to 213 for all fuse and relay info.