We are continuing to answer your boating questions in our new Q&A feature: Ask a Captain! Your Questions, Answered by Experts. A Sea Tow member from Corpus Christi, Texas sent this one in last month regarding trim relays.
Have a question? Send it to us at: AskTheCaptain@seatow.com.
Running the Relay
Q: While preparing to take our boat out at the ramp after a day on the water, our motor trim suddenly stopped working and would not raise the engine. We managed to get the boat on the trailer and not scrape the skeg, but there was no way we could drive home with the engine down. While trying to determine the problem, a fellow boater came over and used a couple of wires with clips to bypass what he determined was a bad relay and raised the engine. I’m not sure exactly how he did it and wondered if you could help. I have a Yamaha 150 HP, 2001 model engine.
John – Corpus Christi, TX
A: Great question and a good teaching opportunity too. Most engines these days, including your 2001 model, have two trim relays that power the trim/tilt motor, which raises and lowers the boat’s engine. One is an “up” relay and the other is a “down” relay. In your situation, the “up” relay likely went bad. Relays might seem confusing, but they are basically a set of switches that help route power. The good news is that in most cases the “up” relay is the same as the “down” relay and in many cases you can just swap the relays to trim the engine in the direction you need it to go.
Since I wasn’t there, it’s hard to know for certain what the good Samaritan did. However, it sounds like he used a few extra wires connected to the good relay to run the trim/tilt motor. Most boat relays have blue and green wires signifying the up and down trims. The blue turns your trim/tilt motor clockwise and raises the engine – *think* blue is for the sky (up). The green wire turns the trim/tilt motor counter clockwise and lowers the motor – *think* green is for grass on the ground (down). In theory, all a person would have to do is use a spare wire with some gator clips to touch the blue wire to 12 volts and the engine raises up, or touch the green wire to 12 volts, to lower the engine down. You’ll have to see how exposed and easily accessible your relays and wire are. You’ll need to be sure to ground the black wire and, of course, disconnect the blue wire from the relay. This will get you home, but you will need to permanently replace the bad relay, which we hope you did. Please note: we do not recommend trying this unless you are certain you know what you are doing.
Side note: Don’t forget that most engines have a pressure release screw on the side of the engine that can be used to release the pressure and lower or raise an engine. However, most engines are too heavy to raise by hand so the motor mechanism and your relays are needed.
Keep the questions coming!