Recommended 12 Gauge 4-Wire and 7-Wire

Updated 09/15/2026 | Published 09/09/2026

Products Featured in This Question

Jacketed ABS Trailer Cable Per Foot

$10.57

12 Gauge 4 Conductor Jacketed Trailer Wire Per Foot

$4.62

TowSmart 14 Gauge, 4 Conductor Wire - 25'

(4)

$35.30

Question:

The 7-way wiring diagrams indicate the need for 10 or 12 gauge wire for the ground. In the TowSmart 14 Gauge, 4 Conductor Wire - 25 Part Number: TS85SR is the white ground a different gauge in this set? If not, is a 14 gauge wire okay for lighting use only? I cant seem to find a 4 wire with a 12 gauge ground wire. Thanks for the help.

asked by: Drew R

Expert Reply:

Hey Drew. The 12 Gauge 4 Conductor Jacketed Trailer Wire item # SWC69FR is the correct 12 gauge 4 wire that has a 12 gauge ground. This wire is sold by the foot.

The Jacketed ABS Trailer Cable Per Foot item # SWC89FR is what I recommend using if you're completely rewiring a trailer with a 7-way connector. It includes 12 gauge wire for the lighting functions, 10 gauge for the the brakes and accessory circuit, and 10 gauge for the ground. This wire is also sold by the foot and includes cooper wiring.

The 25' TowSmart 14 Gauge, 4 Conductor Wire item # TS85SR does not include a 12 gauge ground wire. All the wires are 14 gauge. This wire should only be used for basic 4-function lighting.

What kind of trailer do you have and what do you use it for? Feel free to answer this and throw in any other questions you have, where it says Add Comment.

expert reply by: Jerred H