Newly acquired B25 had a huge wiring mess. I simply started removing wires that were either connected to the old unsafe AC system, connected to nothing, or connected to something that did not work. Not sure how many hundreds of feet of wire I've removed but it is quite a bit.
Unbelievable -- I am glad mine did not look that when I bought mine. My question would be where and how to begin. It was a floating accident waiting to happen.
wires that had 1 end completely unhooked: 3 old unused transducers, 2 sets of vhf radio power and ground, loads of ac wire with a rusted convertor, a broken autopilot, 2 sets of unused stereo wiring with FM antenna wiring and a few sets of wires that went to nothing.