starter won't engage

[cmorris]

I have a 1986 Mercury 45 electric start engine. When I try to start it I hear the starter switch (selenoid) clicking, and the starter doesn't spin. The battery is fully charged.<br />I tried shorting the switch terminals which lead to the starter, and there doesn't appear to be any power (no sparks). My thinking is that the starter switch (selenoid) is bad, and that it isn't sending any power to the starter when I turn the ignition key. Does anyone have any ideas? Thanks in advance.

 

[petryshyn]

Re: starter won't engage

prove it......connect a test-light or voltmeter from starter housing to starter motor stud. Attempt to start and observe if any voltage getting to motor. If voltage present and motor not turning = bad motor(open armature, worn brushes etc.)<br />If no voltage at starter motor stud, measure if voltage getting to solenoid (large stud terminals) There should be voltage from engine block to both large terminals on solenoid when you attempt cranking. (presuming you heard the click)

 

[JB]

Re: starter won't engage

Ahoy, CMorris. <br /><br />This sounds to me like a classic low resistance "open" in a high current circuit. <br /><br />Disconnect, clean and reconnect all heavy wires associated with the starting circuit. Start at the + side of the battery, go through all the wires to the solenoid, solenoid to starter, and from the engine block back to the - side of the battery. <br /><br />Then conduct the continuity tests Schematic describes.<br /><br />Your starter needs several hundred amps to turn your engine over. A resistance of only one ohm in a dirty connection in the starter current circuit will prevent enough current to even engage the bendix gear.<br /><br />Good luck.<br /><br />Red sky at night. . .<br />JB