the sittch onlo has three positions, with the key straight up and downthe power is off if i turn it to the left the starter will turn when i let go the switch turns back to the middle it is spring loaded. if i turn to the right the sstarter turns and the light on the dash is lite.I was told the glow plug is on in this position and after starting i should turn the key back to the middle position. the plate behind the switch is worn out i dont know whqat it said. do i leave it in the right position am i burning the glow plugs for no reason