I have a new lund tach with a 8 wire plug in.. I know it has wires for the low oil,chk eng,hot,and no oil.It also has a light in it.I don't want to hook them up. I have a 1982 35hp evinrude and all I want to do is get the tach to work only. The colors are red,black,grey,yellow,on one side and...