I was blown away by the high price of the Vans stock fuselage wiring harness. A lot of the price is probably due to the labor intensive process of certification
to make sure the connections are tested good. So I downloaded and printed the fuselage wiring plans from the Van's website and got the various pins/plugs from Digikey, along with the hand crimpers from Stein.
I built the harness according to the plan, with some modifications I wanted to better incorporate the Garmin GMU-22 and pitot heat, and a control stick mod. I kept to the dimensions in the plan. I also ordered all of the wire from ProwireUSA.com because the price was right and they had small quantities of all the various wire colors that matched the plan. All together I think I spent under $500 including tooling. It cost me 40 hours of time..... but it was what I wanted in the end.
I have to report that when I brought the harness to the plane this weekend the dimensions in the plan proved right on the mark. I was really glad I bench-built the harness and brought it to the plane because running all the individual wires would have been a bear. As it was I was playing contortionist to get all the pieces where they were suppose to be.
The hardest wires by far to fish to their proper place were the control stick wires. There is a pair of grommets in the mid-plane position where they are about an inch apart and about an inch different in the z-direction; so you have to seriously work to fish through that spot. I didn't have a 16 inch pickup - that would have made it really easy (tongs if you are a surgeon). Instead I took a length of 1/4 air hose and cut a notch in it to catch the wire and move it around to the right place for pushing through the next grommet. I could not once get a wire from outboard to in; in to outboard was the only direction that worked for me.
I think the newer fuse kits have a cutout on the inboard side of the lower F-01435A that my kit did not have; if you have the newer one I think the control stick wires would be easy and finger-doable.
The other thing I did was to install a K1000-8 nutplate in the empty holes on either side of the aft fuel pump fittings, using pop-rivets. This will let me add two adel clamps on each side to take two bundles up past the fuel pump to the console. The plans don't mention this earlier, and it was a real bear to get it done at this stage of the game. I wish I had done that way sooner. Further aft the plans have us use little plastic automotive clips, two on a side. They don't hold well when there isn't much in the bundle but once the bundle is bigger the friction locks seem to hold.
Here is a page showing my saved cart of relevant supplies from Digikey:
Here is a page showing my ordered wire list from ProwireUSA. It isn't 100% of the harness but it is pretty close; also has some non-harness wire too.
You will want to read and research it for yourself to make sure you are getting the right things; it isn't a simple "order this" and build the fuselage harness.
Lastly, I have the Beringer steel brake lines running up the middle instead of the plastic Vans brake line. I'm worried about chafe between the steel and the Tefzel wires. Haven't really decided what to do about that. If I had it to do again I would shrink-wrap the steel line in the center area.... too late now. I might split some thin-wall plastic tubing. I have cloth chafe tape but not excited about it.