Mercury Electric Outboards 222 Thruster Service Manual, Page 50Get this manual
"TM" Models STEP 1Disconnect battery leads from battery2Manually turn propeller shaftShaft should turn evenly and with less than 10 inIbs(11.5kg-cm) of torquePropeller shaft turns easily (can feel "coggingeffect of motor armature); proceed to Step 2Propeller turns too easilyPropeller shaft turns hard (mechanical problem)Broken propeller drive pinRefer to gear housing and motor repair (see "Index")
STEP 1Connect battery leads to battery2Connect voltmeter red lead to Point in schematic diagram, below, and black lead to Point 2Battery voltage should be indicatedRotary Switch Tests OK
1Reconnect wires to switch, following wiring diagram 2Proceed to Step S
If rotary tests faulty, replace switchCheck wiring to see if short in the wiring has caused switch to fail