What is the wiring diagram inside the electrical box where the 7 pin plug is wired into on the trailer

SOURCE: Installing a 7-pin trailer towing recptical on a 1991 Ford F150.

I believe you can look up the manufacturer of the trailer plug kit and find the wiring diagram there. On alot of the trailer plug kits, they have pics and diagrams in the package. The 7 pin plug (truck side) is available with the pig tail set up that plugs directly into the wiring harness for the lights. Then all you would have to worry about is the 2 wires for the electric brakes.

Dale Farr

• 78 Answers
• Posted on Mar 18, 2009

SOURCE: wiring diagram or fuse box diagram-2007 GMC Envoy Denali

Hi there;

Here is the wiring diagram for the trailer wiring for your truck.

Hope this helps
Farrout!

Ned C Cook

• 3433 Answers
• Posted on May 06, 2009

SOURCE: looking for color code (diagram) - 7 wire trailer harness/wiring

If you haven't purchased the plugs yet. The wire color codes should be included in the package.

• If you are using used plugs ck the back of the plugs for color or function of wire
• Wht - ground
• red - stop
• blue - accessory/aux
• brown - tail
• black - Marker
• grn - left turn
• yellow - right turn

SOURCE: I need a wiring diagram for a 7 pin trailer board plug

Here's one
CAV CIRCUIT FUNCTION 1 Z13 12BK GROUND 2 B40 12LB TRAILER ELECTRIC BRAKE OUTPUT 3 L76 12BK/OR TAIL LIGHT (Trailer Tow Relay in PDC) 4 A6 12RD/TN* FUSED B(+) (40A, Always Hot, F8 in PDC) 5 L63 16DG/RD LEFT REAR TURN SIGNAL TRAILER TOW 6 L62 16BR/PK RIGHT REAR TURN SIGNAL CONNECTOR 7 L1 16VT/BK BACK-UP LAMP FIGURE 1: 7-Terminal Trailer Tow Connector

SOURCE: LEFT TRAILER TURN SIGNAL DOES NOT WORK

I have seen once before that the fuse box was bad on a 2003 Dodge 3500. I had power in and nothing out. We had to replace the box. Not cheap! Hope it is simple like a loose connection though. I think I had to pull the inner fender on the drivers side to access the bottom of the fuse box. Pain in the ****, but...