Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 28Get this manual
Test Procedures AWARNING
When testing or servicing the V-6 outboard Ignition system, high voltage Is presentBe extremely cautiousDO NOT TOUCH OR DISCONNECT any Ignition parts while engine I, runningwhile key switch Is on or while battery cables are connectedFailu re to com ply it the following ite ms may result in damage to the ignition system 1DO NOT reverse battery cable connectionsT he battery negative cable is (-) ground
2Use an ohmmeter and perform the following tests 15 Ampere Stator
Tesl eadl10 Belween Blue and Red Slalor eads Between Blue White and AedlWhile Sialor leads Between Red Stator lead and Black Stalor Lead Between AedlWhite SlStor Lead and Black Stator lead Resls ance (Ohms) Scale Reading (I