1990 Johnson Evinrude 120 thru 140, 185 thru 225, 300 HP, P/N 507875, Page 165Get this manual
STEPSENSOR COIL TEST
Ground Test 1Disconnect the two 5-pin Amphenol connectors between the timer base and power pack2Set peak-reading voltmeter to "POS" and "5," liSEN" and "5" on Stevens CD-77 meterf121 3Alternately connect PRV meter between each timer base terminal and clean engine groundCrank engine and observe meter at each connection Any reading indicates sensor coils or leads are grounded Locate and repair ground, or replace timer base4If no reading is indicated in Step 3, go to Output TestOutput Test