It's been raining here most of the day, I noticed my wipers started acting erratically. They'll go up about 1/4 of the way, pause for a moment, then continue up, pausing once or twice more, very briefly. They seem to function fine on full wiper, non intermittent. My aftermarket head unit turns the maps light or dark depending on if headlights are on or not. Today it was switching night/day setting seemingly in sync with the wipers on intermittent on my way back to the office. Where to start?