l have a 1992 Mercury 150. The trim just recently went out, but not all the way. It still tims down but it doesnt wanna trim up. The motor still runs, l can hear it, but when l hit the UP switch, l only hear a click. We tried changing the relays but it still only goes down. Could the motor be bad even though we can still hear it running when we push down? Or would it be a wiring problem?

You might be tripping an auto-reset circuit breaker.
Or, could be a worn out switch, or corrosion/loose connection in the circuit, the ''click'' being an arc.

Have a multimeter or 12V test light? See if voltage is getting to the relay.

Inspect ur wiring for corrosion/loose connections. Keep an eye out for any place where insulation can get chafed & bare wires can come in contact.

Check the switch, fuse box, relays, anywhere there is a connection. Take it apart & polish it till it shines, use sandpaper if u have to.

Solenoid

or

Low fluid in the reservoir.