Garmin :: Why is my Heading Off? Nov 28, 2014 | Why is my Heading Off? 1 Comment admin on November 28, 2014 at 8:19 pm There are 2 known reasons: 1)The synco is probably mis-wired. 2) You will need to have a peanut converter installed to boast the 26Vac 400hz. Mid Continent sells a unit to handle this issue.