The change was described as follows:
- New Trim Sending Units
New trim sending units and changes to the ground wires are in place for all 2012
models. New trim sending units have an internal thermal breaker and as a result,
ground wire location and routing has changed. Previous part numbers will supersede
to new part numbers.
The thermal breaker will activate (open circuit) if excessive electrical current
flows through the trim sending unit. After the thermal breaker cools, it will automatically
If the thermal breaker is activated, the operator may notice the trim gauge does
not work, or the starter motor may not work when attempting to start the engine.
If either of these symptoms occur, check for loose battery grounds at the engine
ground stud, and at the battery.
Based on the visual appearance of the two trim sender devices, I note that on the older version the conductor for the ground is not carried into the sender device, but simply directly attaches to some portion of the engine mount via a ground lug connector.
In the new trim sender (on right) the three conductors from the engine harness enter the device, then a fourth conductor emerges from the device and is connected to two grounding lugs.