Not sure if this is the best place but I didn't see any electrical based sub forums?
I have added a few electrical devices to my 2016 FLTRXS and do not like adding 2, 3, or more additional circuits to the battery. I think it looks bad and adds to the loosening of the battery bolt/screw. Plus it interferes with the plastic cover when you add more than one additional wire. I have a Biketronics BT2180, Heated gear for the colder weather (jacket liner and gloves only), and a light in the detachable tour pack that I wanted to work without the ignition being on. All the circuits are on 12 gauge TXL which is overkill. Probably could have gone with 14 but I overdo everything.
I had purchased a small fuse block and could not find anywhere I was happy with where there was room and easy access. What I did for the time being is I spliced a 10 gauge wire (TXL Automotive) to 3 small single fuse holders for the ATC type fuses. This is better than 3 separate wires on the bolt but you still have 3 small fuse holders tucked somewhere.
Still searching around I found a couple of self contained 3 and 4 space fuse blocks based on the metripack 280 series of connectors and pins. During this research I discovered these are the same pins/connectors used in the factory fuse block. On the NON twin cooled bikes there looks to be 3 blank spaces in the fuse block used for the relay and fuse marked cooling on the twin cooled bikes. I am going to try to install my 3 circuits in the factory fuse box at a later date and will add to this post when I try and if I am successful.
For now I am just going to show what I did to build my harness using the 4 place metripack 280 fuse holder (you can also install 1 relay and 2 fuses in this fuse holder if you wanted.
Here is the crimpers I used. I use 3 different cavities (A, B, C) in the crimper to get a nice tight crimp and then use the other one for the round seal crimp.

Here is the completed fuse block with sealed cover installed.

Here are the seals installed on the wires before stripping. I put a little dielectric grease on the wires so the seal slides easier.

Here is some of the wires with the terminal and seal crimped.

This is a look from the top of the fuse holder. You will see in the empty space there is one terminal. I decided to install a terminal on the feed side and if I ever need to at a later date I can just add the terminal and wire for the load.

In the last picture this is what I plan on installing in the factory fuse box if it is possible. I have 3-12 gauge TXL wires butt spliced to a butt splice made to accommodate different size conductors. There are 3-12 gauge on one side and one 10 gauge on the other to go to the battery. Not shown in the picture are the 3-12 guage conductors with the terminal and seals installed for the 3 loads. I considered using 8 guage but that is what is on the 50 amp main fuse. I figure if I max this out I will be taxing the charging system anyway.
