When you start nosing around adding new equipment you can disconnect something else,,, even if it was originally done correctly.

The Admiral purchased a new 'loud hailer' in St. Thomas and unwittingly stowed it right against the fluxgate compass. The boat would spin around every time I turned the auto pilot on. It took me 3 hours to figure it out. ( mostly because I didn't know where the fluxgate compass was.) Moved the 'loud hailer' and the problem was fixed. Easy!