Parts Needed to Install New Trailer Plug and Junction Box on Trailer

Question:

I’m needing to extend my trailer wiring to reach tow vehicle. Looking at 38656 junction box. However, is there a way to lead the entity wire bundle with outer plastic shield into this box? Seeking a clean and secure connection between existing cable and new extension piece without individual wires being exposed b

asked by: Kautsky G

Expert Reply:

I have a solution for you, and it sounds like you're maybe looking for some sort of plug and play option that you can use as an extender into the junction box, but that does not exist. Your best bet is just to cut the plug on your trailer off and wire the loose wires directly into the junction box; you'll then run a new plug out of the junction box to add the new trailer wiring plug. I recommend using the Junction Box and Installation Kit for Autowbrake Trailer-Mounted Electric Brake Controller # 3430001-JBK since it comes with heat shrink butt connectors and some zip ties to help keep the installation clean and sealed off from any moisture.

Depending on how your trailer is wired (4 way or 7 way) there are some other parts you might need; for a 7 way jacketed wire I recommend using the Deka Wire - Jacketed 7-Wire # DW04914-1 which is sold by the foot. If you need to replace the 7 way plug you can use the Hopkins 7-Way RV Style Connector with Molded Cable - Trailer End - 8' Long - RV Standard # H20046 (8ft long) or 7-Way Molded Trailer Wire Connector, 4' Long # H20043.

If your trailer has a 4 way you can use the Wesbar 4-Pole Flat Connector w/ Jacketed Cable - Trailer End - 8' Long # W787268. If you need 4 way bonded wire to run from the existing trailer wire the junction box you can use the Bonded 4 Wire - per foot # 16-4B-1.