Trim/gauge Wireing 1976 Evinrude Outboard

[MyMotor Boat]

Im trying to hook the trim gauge back up on the boat i bought it wasnt hooked up when i got it so im trying to fix it.The trim gauge has on the back S,G, and L i know the G means ground and i know the L means light but on the S there is 2 post which is got a bar jumping from one post to the other which ties those post togeather.I dont understand what to wire up on those post?The sending unit on the motor is located on the left shock is this the wire that i put on the S or what?



Thanks For Any Help?