tilt/trim units

[DKHunter1]

I have a merc cruiser Alpha one. The trim on the throttle to go up only works when the boat is out of the water. When in the water I have to use the trailer trim to raise the leg. I am guessing it is shorting out when in the water. not sure where it would be shorting from as the wires look in good shape

 

[Chris1956]

The trim limit switch on those Alpha units in on one of the pivot points of the outdrive that is submerged. It is under a plastic cover. Likely the switch guts have gone bad.

The other pivot point is the trim gauge sender. It is a copper pointer and coil that moves as the drive trims up/down.