I have a twin engine boat with merc drives,the port trim pump works great,the starboard side kicks in and out,starts working and then the trim pump stops,then kicks back on after a couple of seconds,when that happens I try the trailer button and that does not help,does that sound like a bad trim pump??
or is there a relay or something else I should look at?
thanks

Check the harness plug in connector to the motor.
It's right on the bracket that the whole assy. is fixed to. It's a round connector that pulls apart revealing a 3 point connection.

In the past I've accidentally kicked mine while squirming around in the engine room and get the exact same problem that you describe ... either that or it stops working completely.

Does the drive stop moving and the trim pump motor continue to run or does it completely shut off?

If the motor continues to run but it looses it's lifting ability the pickups are probably clogged. The resevoir will build up sludge at the bottom and clog the mesh socks on the ends of the pickups. Disconnect the lines and pull the pump out of the boat. Remove the resevoir and dispose of the oil. Clean the resevoir out and also clean the mesh socks.

If it quits completely, it could be a solenoid. Does it quit both going up and down, or just going up? The up solenoid will be attached to the blue wire and the down solenoid will be attached to the green. If all connections are tight you could switch solenoids to see if that cures it too.

Going Through This Right Now Switch The Pump To Either A Tab Or Other Drive Pump And Whatever You Do Dont Try To Adjust The Valves They Are Factory Set And Chances Are You Will Probably Never Get Them Right Again!!!

thanks fot the great info guys.
It ended up been a bad limit switch.
now that thats done,I wonder whats next!

Have you pulled it apart? There's really nothing to adjust. It's a couple of gears and a couple of balls. Not much to really screw up. Outside of the solenoids, the only thing to go bad is the motor itself or the pickups get clogged.