Recommended Circuit Breaker and Wire Gauge for Wiring 7-way Trailer Connector

Updated 08/04/2015 | Published 08/03/2015

Products Featured in This Question

40 Amp In-Line Circuit Breaker - Perpendicular Mount Bracket

(97)

$9.87

12-10 Gauge Butt Connector

(23)

$0.87

10 Gauge Wire - Blue Primary - Per Foot

(103)

$1.80

Ring Terminal - 12-10 Gauge Wire - 3/8" Ring ID

(67)

$1.76

Starter Solenoid - SPST - 12 Volt - 100 Amp - Continuous Duty - Grounded

(12)

$34.51

Question:

I have a 1979 f350 crewcab that I have just built a gooseneck hitch for.I am now wiring the 7 pin plug in the bumper and the 7 pin plug in the bed to a junction box at the rear of the truck.My question is about running the wire for the battery charge post for the plugs.Which components would you recommend from the truck battery to rear of the truck,circut breaker size, battery isolator,wire gauge size,ect....I will be towing a 40ft enclosed race trailer with a winch and a battery and eventually a generator.

asked by: Chris H

Expert Reply:

For a circuit breaker, I recommend using a 40 amp circuit breaker, like the Pollak 40amp In-Line Circuit Breaker # 9510. The wire that runs to the battery will connect to the gold post, and the line that connects to the junction box will connect to the silver post.

Usually, 10 gauge wire is used for the 12V power. I recommend using # 10-1-1. This 10 gauge wire is sold by the foot. To make connections with this wire, you will want to use 12-10 gauge wire ring terminals # DW05705-1 or 12-10 gauge butt connectors # 05732-2.

An isolation solenoid is not required when installing a 7-way connector. However, it won't do any harm to install one if you would like. I recommend the Tow Ready Battery Isolation Solenoid # PK5231201. The solenoid would install between the circuit breaker and the junction box.