How Does 7-Way Trailer Adapter with 4-Way Connector Install

Updated 06/21/2019 | Published 06/20/2019

Question:

Isnt the 4 pin on the 7 round plug in ready to a vehicle with 4 pin making it adaptable between hard wire or just 4 pin plug in?

asked by: Craig P

Helpful Expert Reply:

What you have pictured is a 4-way to 7-way adapter similar to part # C57672. The male side 4-way connector plugs into a vehicle side (female) 4-way to convert the vehicle's connector to a 7-way. The existing 4-way on the vehicle only has the lighting functions so the rest of the wires need to be hardwired to make the 7-way completely functional. The additional wires are to power reverse lights (yellow), the 12 volt auxiliary pin (black), and electric brakes (blue). The white wire is then grounded to the vehicle's frame.

I can't tell by your picture but most 4-way to 7-way adapters also have a female 4-way connector so you retain the one you originally had and you end up with both a 4-way and a 7-way after it's fully installed.

expert reply by: Charles S