Trim Gauge Testing


My boat’s actual trim works fine, but even so, the trim gauge always reads up.

I tested the wires from the sender under the motor all the way to the dash with a meter and found that the resistance varies. So, I took the gauge out to buy another. Before I spend the dough, is there some way to bench test the gauge?



A trim gauge is basically an ohm meter, so a bench test is possible.

  • Connect your battery positive (+) to the positive post on the gauge.
  • Connect your battery ground (-) to the the negative post on the gauge.
  • Momentarily connect a wire from the battery – to the sender post on the gauge.

No wire connected will make the gauge move completely in one direction and a ground wire connected to the sender post will make the gauge move completely in the other direction.

Let me know if you have more boat wiring questions,