My 2003 Mark II tall rig/wing keel Catalina Linear Drive P70 auto pilot worked fine until I upgraded the other eletronics. I changed the binnacle Garmin 545 to a Garmin 1040 with radar, added a Garmin thru hull depth finder, and added a Vesper Marine AIS. Now the auto pilot works for a few minutes and then the boat starts drifting -the screen is lit and pushing direction buttons does nothing. When I put the auto pilot on "standby"" and then back to "auto" it works fine for another few minutes. I am thinking it may be a compass issue (I put the old 545 down below, and I also added a Garmin Heading sensor. ) I moved the 545 antenna and the Vesper antenna a few feet apart (they are both on the stern rail) but there was no change. The Raymarine control box has a switch that was "off" and I moved it to "on" with no change.
I am on the ICW in Florida heading south and need suggestions. I think there is a good Raymarine dealer in Ft. Pierce but I would like to see if I can fix it-I think it is probably something simple.
2003 Catalina 36 Mark II