Added 12 Volt receptacle and dual USB port

In the RV world th 12VDC wire colors are as follows:

12VDC + or POSITIVE is BLACK (I also have a bunch of solid WHITE wire with a solid color stripe.)
12VDC - or NEGATIVE is WHITE.

In the automotive world it is pretty much like this:
12VDC + or POSITIVE is solid RED
12VDC - or NEGATIVE is solid BLACK

When batteries are both used in both worlds of RV and Automotive you see both wiring colors used...

Most trailers use the popular JENEN CAR RADIOs and guess what colors they use for 12VDC +POSITIVE and -NEGATIVE wiring... RED and BLACK... They coe out of the chassis that way - Can't change them...

When a old timer see's a RED WIRE on TOP of a BLACK WIRE on a terminal strip he will go bananas hehe...

I have a couple of spots in my trailer I added using the USB ports for charging cell phones and tablets...

Roy Ken

Those are nice but keep in mind that the little regulator in there is making 5VDC constantly and is a parasitic drain.

Great idea and a good looking installation!

Not to be too nitpicking but I learned this last year: When powering DC circuits to a battery, anytime the circuit is interrupted between the battery and the device and multiple circuits are connected, a fuse should be between the devices and the first connection. I understand you have a fuse between the terminal block and the battery. That may be all you wish to mess with, I just thought I'd mention the improved way to protect all your wiring.

As far as parasitic drain, I store my trailer in the driveway plugged into shorepower so hopefully the float charger on the converter takes care of that.If we end up drycamping where it becomes an issue I can always pull the fuse. As far as fuse protection, I have a 20 amp fuse on the wire from the battery to the fuse block (in the picture it looks like a terminal block because I don't have fuses in it yet), then the hot wire to the receptacle side is fused and the hot to the USB is fused.

Nice install! Yes, parasitic drain is only an issue when you are dry camping and concerned about amp-hour usage and battery drain. The converter makes 12v all day when plugged in so no issue if you camp with hookups. Since we do a fair amount of dry camping, I installed a dual cig socket and I use one of the twin USB adapters that you plug into the cig socket so I can remove it when not in use.

RV wiring is unique...the 120v wiring follows the conventional color coding just like your house. Most of the 12v wiring in the TT seems to be like heavy gauge white zip cord, with a colored tracer run on the (+) side.

Great install. You could always take some colored electricians tape and wrap it around the individual wires to identify the wires to RV convention.

On the parasitic drain, anytime you leave your TT at a dealer for work for a few days or so, these things will drain the battery. I installed one of these in our TT and twice now I've picked up our TT at our dealer only to find a dead battery.

If you need to leave your TT somewhere for any length of time and it won't be plugged into shore power, pull the fuse. Or install a disconnect switch.