1974 Johnson 135 HP Outboard Motors Service manual, Page 127Get this manual
9-15 4If the ohmmeter indicates less than ohms reSistance, regardless of the trim pOSition, the sending unit lead is shortedIsolat the hort with continuity meter and repair or replace lead as required 1 NOTE i:i::!1
The sending unit lead is sometimes pinched between the stern bracket and the hydraulic lift assembly5If ohmmeter indicates an open circuit (very high resistance) either intermittently or constantly, check the sending unit circuit for continuityStart at gauge connection and work back to sending unit stud at trim cylinder (port cylinder)Repair any open circuits foundIf ther is continuity to cylinder, then the problem is internal to the trim cylinderRemove the hydraulic lift assembly fr om motor and disassemble After disassembly inspect all parts, especially the stud, pick-up spring, ball and windings for contamination, corrosion and wearCheck the pick-up spring for non- conductive coating with an ohmmeterCheck the ground springs for proper contact with the cylinder wallContact sp ring should project past the edge of the bearing by approximately 1 16"See Fig9- 16