12v Socket Install

rjgvt · May 25

Installed a 12v socket in my 2024 GMC Sierra GMC 2500HD AT4 today. Goal was to connect the 12v socket to the Aux battery. I've been trying to get a 16 gauge wire through the bottom of the firewall feedthrough on the drivers side. I tried a stiff wire, X-Acto knife, long skinny screw driver, etc. I was able to make a small hole and get a piece of 12 gauge house wire through but was a pain getting the other wire to come through the nipple on the inside.

I got a Diablo 1/4" spade bit at Ace and was able to drill a hole big enough to get a 16 gauge wire through by bending the edge over the end of the long skinny screw driver and pushing it through the hole from the engine side. I taped that wire to one of the 12AWG wires and used a drop of oil spread on the tape and pulled it through the firewall. Taped the other 12 AWG wire to the first one and pulled it through.

I used Wirefy connectors with built in heat shrink and an Ancor crimper, got both from Amazon. 12v socket is a Bulldog Winch 12v 20A part number 20286. Bulldog Winch wanted a lot for shipping and got it from etrailer. It's rated for 20A, fused it at the Aux battery with a 15A fuse. Connected the negative wire to the ground bolt for the aux battery on the top of the fender. It comes with 3 different mounting options. I used 12 AWG red and black wiring from a local West Marine along with 3/8" split loom from West Marine. Split loom claims it is self-extinguishing. Secured the 12v socket with Scotch Extremely Strong Fasteners. Not sure how it will work but will probably have to hold on to the socket when connecting anything to it.

See next post for more pics.

Edited May 25 by rjgvt

rjgvt · May 25

First pic is wires inside the cab from the feedthrough.

Second pic, socket is mounted to the lower dash to the left of the console with the Scotch fastener.

Third pic: I moved the excess wiring/loom away from heat duct output. I tucked the excess in the side panel. I might move it more to the right of the heater duct.

Fourth pic: Wiring in loom from dash feedthrough.

Fifth pic: Wire loom from feedthrough to aux battery.

rjgvt · May 25

More pics. I ty-wrapped the wiring/wireloom to the other wiring in the engine compartment away from any liquid carrying hoses.

Last pic is where I mounted it before wiring it.

rjgvt · May 25

Just wanted to add that to make it easier to work on the feedthrough from the engine side, I laid a moving blanket across the front of the truck and engine. I used a ladder next to the front of the truck with the blanket protecting the truck. I initially tried working next to the drivers side on a HF step stool and was not able to see what I was doing.

rjgvt · May 25

Rerouted the wire loom under the dash to behind the heater duct and tucked the excess in the console panel. Also some finished pics.

Plan is to use the USB socket thing for plugging in my Garmin Inreach Satellite Communicator. My last truck had two 12v sockets, one was always on and used it for charging the Garmin every day or two. I could charge it in camp but would probably forget it so I leave it in the truck during hunting season.