We bought a portable fridge/freezer to be able to have more freezer space. It works with AC or DC. Trying to come up with a viable solution for installing a 12 v cig plug in bay that has my 12v fusebox. I thought about creating it's own circuit as there are some open slots. Just not sure exactly how to do that. Appreciate any and all ideas.
You must have a 40 footer as yours is the same year as ours but the compartment is a little different compared to our 36 foot model. Download the schematic found on this site and compare the wire code on the schematic with the white tape on the cables in your photo you attached to the post above. Connect to the house circuit and not to the engine side. Make sure to fuse any connection you make in case of a short. The fuse/cb should be in the compartment in the photo.
Pierce
The hardest part would be finding the right terminal to go into the existing fuse block. It's probably easier to add an external inline fuse. I'd just pull power off the stud on the left of the large inverter fuse at the bottom left.
Amazon.com: Dongge 12V/24V Fixed Thread Cigarette Lighter Socket Extension... (https://a.co/d/inNxRvr)
Here is a kit that has everything you need. Red goes to the post on the left of the inverter fuse, black goes to the ground post to the right of that with the rest of the black wires.
Basement freezer was an option in 1990. Here's a schematic that shows the wiring back then. One of those on your panel now might be for a freezer. You should see if a similar schematic for your year coach is in one of your owners manuals (binders).
Be careful with a cig lighter; they can wiggle out with vibration. Fix in somehow or remove it and use a two lead screw terminal block.
Lots of stories of basement freezers loosing power and owners not finding out until they smell it.
Strongly recommend a remote thermometer with an alarm as a safeguard.
Also to run the wire to the other side of that bulkhead wall, just use a magnet to make sure you are away from any steel tubing and you will only be drilling through .090" of fiberglass, 1.5" of foam, and then another .090" of fiberglass.