Can a 7-Way Round Pin on a Peterbuilt 335 be Adapted to a 7-Way RV Style Connector

Question:

I have a peterbuilt 335 and i wand to wire up an adapter for my 7way round plug that i can use for standard 7way blade conection on recreational trailers

asked by: Jeremy D

Helpful Expert Reply:

The 7-Way round on your Peterbuilt is likely the big rig style. This style does not have the same functions as an RV blade style 7-Way connector. On the big rig 7-Way the brake light and turn signals are on separate bulbs and typically RV style taillights are combined where the brake lights and turn signals are on the same circuit.

What you can do is use a converter to combine the brake lights and turn signals. Converter # RM-732 has a white ground wire, red brake light wire, yellow left turn signal wire, and green right turn signal wire. The output side has yellow for combined left turn and brake lights and green for combined right turn and brake lights.

I have included a link to our help article on trailer wiring that has diagrams of various trailer connectors (vehicle and trailer sides). Please note that since there is no industry standard color code for wires you will need to go by function. You can test the wires on the truck using a circuit tester such as # PTW2993 to determine function.

expert reply by: Michael H