Hello. My grandson and I are unfamiliar with this but try to learn: We bought a 30 hp Mercury 1996 30 hp outboard together and now we try to hook it up to the boat. However we are not able to find where the + and - connections from the battery are supposed to be connected. There seem to be a small switch (solenoid) where we may connect one of the cables (+?), but in such case, where do we connect the -?. Could you please help? Thank you.

