See these pictures.
These pictures(Related Link) only apply if you have wheel steering and a round pedestal. Richard and I installed ours exactly the same way. We used a heavy rubber(6") coupler available at Lowes. It provides a solid mount and I found the stainless clamps to be better than the ones shipped with the Simrad. Slit the coupler and then carefully remove about a 3/4" section to get a good fit. I drilled a hole in the forward-center of the pedestal, just above the rubber coupler. I used a rubber grommet over the wiring to seal the hole. I already had 12 volts under the pedestal so just spliced into it. But I have had to run wiring from the wind instrument. So far I have not connected the GPS. To run wiring up the pedestal I drop a piece of wire down from the new hole with a small screw attached at the end. Then I go underneath and use one of those magnetic wands to reach in and pull out the messenger wire. Usually requires that the binnacle be removed so that I can see down in there from the top.
