The trailere switch normally raises the drive to the full up position for
trailering. The trim switch will lower the drive to the normal operation
when pressed for down. It will then adjust the outdrive up or down but only
within the normal operating range. The trailer switch has to be used to get
the drive fully up for trailering. There is a switch on one side of the
outdrive where it pivots that keeps the trim switch from moving the drive
too far up. The trailer switch bypasses this switch. The other side of the
outdrive pivot has the sending unit for the trim gauge.

You should get a clymers manual for mercruisers.

wrote in message
...
Well after looking everything over I decided to drain the oil from the
cylinders by cracking open the fittings, and to my surprise the
cylinders still didn't compress! So I rotated the cylinder piston rods
and tried to loosen them a bit and after that the port side cylinder
works fine! Now I still have to work on the starboard cylinder to get
it to work. Halfway there anyway. I was thinking of trying a ratchet
strap to get it to compress.