Installing 7-Way Trailer connector on 1992 Ford Pickup

Question:

I need to install a 7 blade socket on my truck, and am confused as to what wires I connect the blades for the left turn/stop and right turn/stop to. Do I need to run a jumper from each the brake light power and turn signal power to the socket, or just one or what. I think I understand it all with the exceptions of pins 5 and 6: 1. Ground from plug to frame 2. Trailer brake input from brake controller to plug 3. Jumper from tail light wire on truck to plug 4. Constant power w/ breaker 5. Left Turn/Stop should this be two wires, one to left turn and one to brake lights? 6. Right turn/Stop same question as above 7. Jumper from reverse light to plug

asked by: Phillip S

Expert Reply:

I think I understand your confusion. The taillight system of your 92 Ford pickup uses what's referred to as a combined taillight system, which means that the right turn and brake light signal is combined and carried on one circuit and the left turn/brake light signal is combined and carried on another circuit. So, if you're looking at the front of the 7-way blade style plug, the 12-volt power feeds the pin in the 1:00 position, right turn/brake feeds the pin in the 3:00 position, brake output to the pin in the 5:00 position, ground in the 7:00 position, left turn/brake in the 9:00 position and taillights in the 11:00 position. The pin in the center is used for a reverse lamp feed if needed.

One of the easier ways of doing this would be to install # 118316 along with # 37185. The 118316 would plug inline with the truck's taillight wiring harness, and the # 37185 adapts that to a 7-way. There will be 4 remaining wires, blue carries the brake controller output, black carries 12 volts from positive battery terminal through a # 9510 circuit breaker, the white wire grounds to the truck frame and the purple wire is for reverse lamps if necessary.

I'll link you to our trailer wiring help article which contains several wiring diagrams that you might find helpful.

expert reply by: Mike L