Wiring a 7-Way for 12 Volt Power to Maintain a Trailer Battery Towed by a 2011 Chevy Colorado

Question:

I have a 4 pole harness installed and bought an adapter to convert it to a 7 pole. The 7 pole converter has an extra black wire to hook to the battery power source so that my trailer battery will charge while I tow it. Which wire on my truck do I tie this black wire to?

asked by: Dave D

Expert Reply:

The wiring on a vehicle and in a trailer connector is not sufficient to up-charge a trailer battery unless it is a smaller break away battery. The wiring can maintain the current charge level on the battery but a battery charger is recommended to up-charge the battery.

Since your truck does not already have a 12 volt wire at the back, you will need to hardwire one from the adapter you have to the positive terminal on the battery via a 40 amp circuit breaker # PK54540 and using about 20 feet of wire # 10-1-1. Connect one end of the wire to the adapter black wire. Route it under the vehicle, avoiding areas that may pinch or burn the wire, and then up through the engine compartment near the battery.

Depending on how you route the wire you may have some extra left over which will be needed. Mount the circuit breaker to the metal of the engine compartment. Connect the wire you routed to the AUX terminal on the circuit breaker saving the extra wire. Then from the BAT post on the circuit breaker, attach one end of the remaining wire and then attach the other end to the positive battery terminal. On the 7-Way adapter make sure the white ground wire is attached to the vehicle frame.

This will allow you to maintain the charge level of the battery but will not up-charge it. For a battery charger I recommend using CTEK battery charger # CTEK56674. I have included a link to a video review for you.

expert reply by: Michael H