Trailer rewire - What gauge for 7 pin?

[j20brett]

I'm about to start the rewire of my carhauler (brakes on both axles), as the factory wiring leaves plenty to be desired with all the pinch connectors. My question is, what size wire is needed? I've already got 25' of 7 strand, 14ga wire. But in further searching, it looks like 12ga is the recommended minimum for aux power, brake and ground circuits. All my lights are LEDS. Am i going to regret going lighter?

 

[aczlan]

Per:

On each individual electric brake magnet the amperage draw would be 3.0 to 3.2 max amps at 12 to 13 volts on 7-inch brake magnets and 3.2 to 4.0 max amps at 12 to 13 volts on 10 and 12-inch brake magnets. The max amperage draw for the brake magnets on a single axle trailer (2 brakes) would be 6.3 to 6.8 max amps on a 7-inch brake system and 7.5 to 8.2 max amps on 10 and 12-inch brake system. The amps will be higher if using a tandem axle or triple axle trailer.

So, for 4 brakes you would be looking at 12ish amps for 7" brakes, or 16ish amps for 10/12" brakes.
I would probably do 10 gauge for the ground and 12 for the brakes, aux power, etc.

Aaron Z

 

[PurfsMcGurfs]

I used to rewire boat trailers when I was a marine tech. 14ga for turn, stop, running lights and, reverse lights if you have it. Electric brakes I ran 12ga for single/double axles or 10ga for triples. Aux power and ground can be 12ga, you'll never really get a ton of amps through the 12v leads. Most manufacturers use 14 or 16 anyway. The 12ga will easily charge an onboard battery during a roadtrip.

 

[GLTHFJ60]

I used to rewire boat trailers when I was a marine tech. 14ga for turn, stop, running lights and, reverse lights if you have it. Electric brakes I ran 12ga for single/double axles or 10ga for triples. Aux power and ground can be 12ga, you'll never really get a ton of amps through the 12v leads. Most manufacturers use 14 or 16 anyway. The 12ga will easily charge an onboard battery during a roadtrip.

This is what I did. Works great.

 

[arse_sidewards]

x3 on the 12 for brakes and whatever comes in the 4-wire trailer wiring and lights kit for the rest.