I am encountering a problem with the consistency of powering up and down my trim/tilt unit. I have a 2000 Mercury/Yamaha 4 stroke outboard. It was intermittent taking several button pushes(hearing only a click) before the trim/tilt would work. I followed the Repair manual's instructions and cleaned all the connections(all looked good) and put dielectric grease on. I pushed the cowling button and it took several tries before it worked But it worked every time after that. I had this same result last year. I at first thought the hydraulic fluid was low, but when I checked the level, it was full. I did follow directions and had the motor at full tilt. Is there another area that I need to check? Right now it works fine, but after it sits, it starts intermittent response again. Is there a possibility of a leaking internal seal? There is no leaking of the unit visible. The unit is always full of fluid. Any advice will be appreciated.

We had the same problem on a 40 hp 3 cyl EFI outboard. I checked the resistance of the motor against the value in the manual, it was way too high. I chopped the motor leads near the motor, thinking it was the wiring, since the wires flex when the motor tilts, and we operate in salt water that is hell on wiring.

Before ordering a new motor, I tried hooking up a battery charger to the motor leads. The motor turned over slowly, then faster and faster. Since we're short of money (we're a non-profit community sailing and windsurfing club, good luck finding rich donors for that), I put the motor back in and it's been working as well as we need, we have other problems (ever had someone get fuel for your motor, and come back with a load of diesel?).

The problem was that the motor commutator corroded slightly when it was sitting, and the voltage from the relays (probably also slightly corroded) wasn't enough to burn off the corrosion.