Larry,

More likely IMO, since you had the alternator checked by folks who make
money selling alternators, is the trim pump motor is defective. However, if
your alternator belt is old and has been slipping (squealing) it may have
become glazed and need replacement. Sometimes adjustment is not enough for
an old belt.

Belts are cheap. I'd replace mine if it is not virtually perfect if I had
the slippage you describe. I'd go from there to more complex expensive
issues. Is your tilt trim fluid reservoir full? How many amps are being
drawn by the trim motoer? How many should be drawn? Is the switch
connection perfect? Are all connections secure and free of corrosion?
Disconnect the battery and check the resistance in the circuits going from
the switch to the motor. Then check the resistance from the batter
connection to the switch. Any resistance?

Lots of possibilities but I like to go from the easy cheap to correct to the
difficult expensive to repair.

Again, good luck.

Butch
"Larry Crowe" wrote in message
...
Thanks for the info. My local marina mentioned that I may need a rebuild
or replacement alternator . I pulled the alternator and
had it bench tested under load at an automotive alternator re builder and
they said that and it seemed fine. So I guess maybe the alternator is
still really defective since I secured the belt when reinstalling..
Thoughts ?? Larry

Butch Davis wrote:
Larry,

If the trim pump has a direct short in the motor it puts a large
electrical load on the system when used against any resistance
whatsoever. When the engine is running it would put a large load on the
alternator. If the alternator is belt driven it could well cause the
alternator belt to slip. OTOH, it could simply be that you need a new
belt or to adjust the old belt.

Good luck.

Butch
"Larry Crowe" wrote in message
...

Get a squealing noise from the water pump /power steering belt areas
whenever I trim up or down. What I noticed is that it does not squeal
when trailered out of the water just trimming off the battery.. If I
muff it with engine running I get the squeal when trimming, don't really
understand why ?? Larry