1997+ Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-826148R2, Page 83Get this manual
Alternator System Test 9 AMPERE STATOR IMPORTANT: Rectifier (optional accessory) must be functioning properly for accurate test results to be obtained1Remove RED lead from (+) terminal of rectifier2Connect RED (+) ammeter lead to rectifier (+) terminal and BLACK () ammeter lead to RED rectifier lead3With engine running at the indicated RPM, the ammeter should indicate the following approximate amperes: AMPERE STATOR (SN-0G589999BELOW)
RPM Ampere Stator Idle 1000 2000 3000 AMPERES 0.2 6.5 9.0
5If cranking voltage is acceptable, disconnect larger diameter RED harness wire from starter solenoid terminal6Remove smaller diameter RED wire (sense lead) from starter solenoid terminal and connect to the positive (+) terminal of volt transistor batteryGround the negative () terminal of the volt battery to the engine7Connect RED (+) ammeter lead to larger diameter RED harness wire, and BLACK () ammeter lead to POSITIVE terminal on starter solenoid8Secure starter wires away from flywheel9With engine running at the indicated RPM's, the ammeter should indicate the following appropriate amperes: