Power bolster
 

Running out of time to get my boat ready for the upcoming holiday weekend. Only have one day reserved to get it waxed, mufflers and gps installed. Have an issue with my passenger power bolster. Boat is new to me. When I uncovered it this spring I noticed the pass bolster operated with the battery switch off, also the switch works backwards. With the stereo playing if you hit the switch the stereo goes out. I am thinking issue with a ground wire. So the question is where does it get its power from? Under the dash-engine compartment-under rear seat?

Steve