Posted for "Paul Bricker" <pbricker@earthlink.net>:

 Jay,
 
 
 
First, let me emcourage you to keep the harness intact and run the cable
 thru a hole in the firewall. My original installation in my ES I cut the
 harness and routed it thru a bulkhead connector. I had an intermittant
 conatct that caused several problems until I tracked it down. I ordered
 another harness from Klaus and started over.
 
 
 
 You are right that you need a large hole to pass the connectors thru the
 firewall. I used four alum plates (.050?), each about 3 inches square, with
 a ¾ inch hole in the center, and four bolt hoes in the corners. I cut a 3/8
 inch slot from one side to the center hole in each. Two plates went on each
 side of the firewall, with the slots on adjacent plates offset 180 deg.
 Rubber grommets protected the cable where it went through the plates, and
 the cavity between the plates was filled with high temp silicon caulking.
Four through bolts/etc finished the deal. The only fire path is along the
 cable itself. Whether this provides a robust and finished appearance is
 beyond me.
 
 
 
 I’d take a photo but the plane is in the paint shop. Perhaps I’ll be able to
 find a picture in the building files if there is interest.