Start from the top.
Ed, I have recently had to put addon elect. equipment on my pedistal guard.(GPS, autopilot, RAM mike) I have removed the compass and passed a fish tape, and one time a weighted string, down the pedistal to a hole I could see. I then reach under the ped. and pulled the tape/string out and attach the wires and pull back through. I have drilled a hole in the plastic binnacle and routed the wires. Not really clean and neat but it works. I suggest tyraps where possible to keep cables together. I have a H 33.5 and no wires are led through the ped guard. I can get to the bottom of the ped by removing a cockpit floor panel. Good luck.
