I have a 2001 mercury150 saltwater. Ive replaced both relays and the trim still wont work. It just quit suddenly one day. Every now and then it'll show a sign of life. Any ideas?

sounds like a pump might be going bad

Knock on the tilt/trim motor with a screwdriver. If that helps it work the tilt/trim motor is going bad. If you knock on it and nothing happens but you hear a clicking sound inside the cowling, the tilt/trim motor has already gone bad.

make sure that the purple wire is intact. I think its purple or could be green.

Also check the relays.

If you only have one trim switch it could be it. Take it apart and clean it. If you have 2 or 3 at other locations try each before going further.>>Every now and then it'll show a sign of life. Any ideas?<< That sounds like a dirty switch to me. Simple fix if it is.

(its green and blue wires)..i just had to rebuild my whole trim assembly..sucked but alot cheaper than buying a new one

I just went through this very thing with my 250. First try the above screwdriver handle whacking the tilt motor while holding the up or down switch. If works motor going bad. Next try the different switches on the boat. If works the initial switch is bad. Next listen for the relay clicks. There is probably two relays a up and a down so if the motor will go up or down but the other direction its a relay. Next buy a maintenance book if you are a fair mechanic and if not time to find a mechanic.

Replaced mine , it would work then not , found out water some how got inside the motor part of the pump .

You could follow the leads from the trim motor into the cowling and unpug the wire terminals. Apply 12 volts (from your battery) across the wire terminals. Then you'll know for sure if it's the motor. Sounds like it's your motor. Mine was a 2001 Merc 150. Same exact symptoms.

Is it wrong that everytime I see this title, I snicker

Thought it was just me....

Watched a mechanic drive himself crazy one day trying to figure out a trim problem. Changed wiring harness and relays. Ended up being the switch on the deck was shorted. He checked the trims on the shifter and the motor, just never walked to the front and checked that one. I think he was expecting the worse and it never rang a bell. 3hrs of working and it was a 10 min fix to replace the front trim switch. I bet from that point on he always walked to the front and checked the deck switch

thanks, its my old mans boat. Pretty sure its a bad motor.

Me too.