Hooking up12 volt outlets?

Huron (above) speaks wisdom to you.  Unlike a car or truck, the frame of the camper is hooked to the ground of the 120v. system.  If you remove the front panel of the WFCO converter, you will see it.  Good luck!

Hi Everyone,  I needed some shelving for my 151 so I built a small unit out of bamboo cutting boards. The cutting boards were sold in a set of three and inexpensive. ($8.00 at Ross Stores) The shelf was then attached to the right side of the entertainment console. Wanted some 12 volt outlets but was afraid to drill  large hole in the cabinets. Instead I installed two outlets to a bamboo kitchen utillity box then attached the box under the top shelf. ($4.00 at Cost Plus) The outlets are wired with 12 gauge wires and runs to a junction box located under the bed ledge. 10 gauge wiring will be used from the junction box to a open slot at the DC power panel. My question is how to hook-up the negative wire at the power panel. Is there a negative ground strip in the area? I've also prep a second branch at the junction box for a future outside outlet. Hope the pictures attached will go through. Thanks, ajzuma. Hope this makes sense.