7-Way Trailer Connector on a 2005 Chevy Silverado is Not Charging the Trailer Battery

Updated 03/08/2013 | Published 03/07/2013

Products Featured in This Question

7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket - Vehicle End

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$43.19

NOCO GENPRO On-Board Battery Charger - AC to DC - Waterproof - 3 Bank - 12V - 30 Amp

(43)

$324.95

Cordless Circuit Tester

(15)

$19.26

Question:

a 2005 silverodo the aux. wire to charge trailer batt. not charging batt. where do i begin !

asked by: Jim

Expert Reply:

First, the wiring on a trailer connector is too small to charge up a battery on a trailer. It can only keep the battery at whatever charge level the battery is at. But if the connector is not showing power on the 12 volt circuit on the vehicle 7-Way (1:00 position if looking at the face of the connector) then there is a common cause. To test this circuit, use a circuit tester like # PTW2979 if you do not already have one.

From 1999 to 2006 GM may or may not have made all the connections under the hood for the tow package wiring. On some trucks, you will need to finish making the connections under the hood. I have included a link to an FAQ article that will help you.

Once you get the 12 volt circuit working, and you are sure that the matching pin on the trailer connector is going to the battery, it should provide a maintenance charge to the battery.

To charge up the battery you will need to use a battery charger like # NOC74FR. Unlike traditional trickle chargers, this charger will not overcharge and damage a battery. I have included a link to a video review for you.

expert reply by: Michael H