1985 Mercury Outboard V-300 V-3.4L Shop Service Manual, Page 26Get this manual
IGNITION COIL TEST IMPORTANT: Ohmmeter tests can only detect certain 'aulilin the Ignition callsRepllce Ignition coli, If ohmmeter readings (lilted In chart, following) are not .s specified" call lestOK, and call I, stili suspected of being faully, use Mulll-Meter OVA Tester (91-99750), or voltmeter and DlrectVoltage Adaptor (91-89045) to thoroughly check calllDisconnect wires from the posi tive (+) and negative (-) coil terminals2Remove th spark plug (hi-tension) lead from coi tower3Use an ohmmeter and perform the fo ll owing tests:
RIII.nce Selle Reldlng
IGNITION (KEY) SWITCH TEST (Commander)
1Disconnect remote control wiring harness and instrument
panel connect orN OTE: Refer to wiring diagram at end of Ihis section for correct identification of connector terminals
2Set ohmmeter on scale for the follow ing tes ts:
Til' Le.d, to
Between (+) and (-) Coil Terminals Between Coil Tower and (-) Coil Terminal