How to Activate 12 Volt Accessory Circuit of 7-Way on Truck without Factory Wiring

Published 10/16/2019

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10 Gauge Wire - Blue Primary - Per Foot

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40 Amp In-Line Circuit Breaker - Perpendicular Mount Bracket

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$9.89

Question:

I rigged my trailer 7 way plug as per your diagram for a dodge ram truck. all the lights work fine but there isnt any power to the 12v aux feed with or without the truck running. thanks

asked by: Kenneth S

Expert Reply:

Sounds like you hardwired the install of a 7-way like the # HM40975 to a vehicle that didn't have trailer wiring prior. So to activate the 12 volt accessory circuit of the connector you'll just need to run a wire from the 1:00 pin of the 7-way with 10 gauge wire like part # 10-1-1 (sold by foot) through a 40 amp breaker # 9510 to the positive pin of the battery and you'd have the circuit active.

Even on some vehicles that have factory 7-way wiring this method is required as they don't all come with this circuit active.

expert reply by: Jameson C