1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 157Get this manual
3Reverse the ohmmeter leads and note readingAn infinite (very high) reading in both directions indicates the diode is openA low ohms reading in both directions indicates shorted diodeA normal diode will read resistance in one direction and infinite reading in the other direction4If diode is defective, replace power packthe 155 Model ignition systemthe port side side are two identical ignition systems, and the sameTherefore, the checks will apply to starboard ign ition system
In troubleshooting and the starboard should be checked each side, port and
Charge Coil Tests 1Short testDisconnect two -wire connector and plug both ends into adapterSet meter switches to negative (-) and 500Clip black meter lead to armature plate, place red meter lead in pinhole "A Crank engine and observe meterMove red meter lead to pinhole "B" and crank engineAny reading on either test means charge coil is shorted Repair or replace charge coil2Output testWith red meter lead in pinhole "B" place black meter lead in pinhole "A" Crank engine and observe meterIf meter indicates he voltage listed below (or higher), charge coil is OK If there is no meter reading, replace charge coilCharge Coil Tests