What Fuse/Circuit Breaker is Needed For The Charge Line When Adding Curt Trailer Adapter #C57672?

Updated 09/15/2022 | Published 09/14/2022

Products Featured in This Question

Curt Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat

(510)

$37.40

Wiring Kit for 2, 4, 6, and 8 Brake Electric Trailer Brake Controllers

(168)

$55.67

40 Amp In-Line Circuit Breaker - Perpendicular Mount Bracket

(100)

$9.96

Circuit Breaker - 20 Amp - Perpendicular Mount Bracket - Cycling Auto Reset - Metal - Type I

(21)

$6.34

Circuit Breaker - 30 Amp - Perpendicular Mount Bracket - Cycling Auto Reset - Metal - Type I

(35)

$10.48

Question:

It wasn’t clear at first, but I figured out I have to run a 12 gauge wire from the black wire on this adapter up to the red battery terminal, and put a fuse in line with that. However, the documentation doesn’t say what type of fuse to use. I see 30 amp and 40 amp in different answers. Which is right, will both work, what’s the difference?

asked by: Josh L

Expert Reply:

I recommend using the Wiring Kit # 5506 for running the wiring on your 2019 Mazda CX-5 with the Curt Trailer Connector Adapter # C57672. This kit includes duplex wiring for both the charge line and for adding a brake controller. The kit includes a 20-Amp # PK54220, 30-Amp # PK54230 and 40-Amp # 9510 circuit breaker. The 20-amp breaker is typically used to power the brake controller for single and tandem axle trailers. The 30-amp is typically used to power the brake controller when used when a trailer has 3 or 4 braking axles. The 40-amp is used for the charge line circuit. On a smaller vehicle like your CX-5 I recommend using the 20-amp for the brake controller and the 30-amp for the charge line since anything you tow will not have a lot of electronics and require the higher amperage from the vehicle battery.

expert reply by: Bud M