New starter, new battery, still just clicks when key is turned. 1990 3.0 mercrusier.

[Sabbathday207]

New starter, new battery, still just clicks when key is turned. 1990 3.0 mercrusier. The motor will turn over when I “hot start” the starter with a wrench. But when the key is turned it just does one click. Ignition was replaced 2 years ago by previous owner (I was told). Any ideas?

 

[poconojoe]

Sounds like you have a dirty connection somewhere.
Disconnect every connection one at a time and clean to shiny new.

Sometimes a cable can get corroded internally. Check all cables at all connections for green corrosion.

 

[Scott Danforth]

by shiny new clean, he means with a wire brush chucked up in a drill, or 150 degree sand paper, and clean the connections until they are clean enough your wife's mother would eat off them.

 

[dingbat]

Starter to battery cable is in tact.
Solenoid circuit has an issue.

Check the wires at the starter solenoid for 12.7 VDC when turning the ignition to start. If that doesn’t work, pull the wires off the ignition switch and jump. If the starter turns over the ignition switch is bad.

If it doesn’t turn over, you have a downstream issue. Start cleaning connections starting with the ones off the switch. Look for any corrosion or wire damage. Connector crimp is always suspect when vibrations is present

 

[Chris1956]

Some MerCruisers have a slave solenoid on the block. The ign key start circuit energizes the slave solenoid. The slave solenoid then energizes the solenoid on the starter, causing the starter to spin and engage the flywheel. Not sure if your 3.0L motor has a slave solenoid, but my 4.3L MerCruiser did.

BTW - was your new starter a rebuilt one or brand new? The rebuilt starters can have worn solenoid plungers which stick in their tubes. They just click for some tries, until they decide to work properly.