I have a mariner 90 approx 1990. I went to take it out on Thursday night, and the trim wouldn't go down, when I press UP I can hear the motor kick in, when I press DOWN it is totally silent, I then manually lowered the engine and the trim will bring it back up without any issues.
Agree with whisper. Either faulty switch or more likely, wiring. Invest in a multimeter and do a continuity test. Outboard manufacturers in their lack of wisdom failed to use tinned wiring. Easy to identify, with multimeter. If the wiring is oxidised, then you can strip in new wiring. Lightly sand the ends on the solenoid and lightly grease. Check all bullet connectors.
Sula
