Solenoid Voltage

OSGFII

Cadet
Joined
Dec 11, 2011
Messages
10
The pinion on my starter motor is spinning, but not rising up to engage with the flywheel. My battery is reading 12.3V, which is also what I am getting on the wire leading into the solenoid. Coming out of the solenoid I am reading 11.4V. Is my problem insufficient voltage to the starter? What's the fix? Just buy a new solenoid?
Aloha,
Derek
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Solenoid Voltage

First.... run good known jumper cables from a good known fully charged battery directly to the electric starter. If the starter cranks the engine over normally, then obviously the starter is okay.

If the above cranks the engine as it should, remove, clean, then retighten all cables/wires that pertain to the starter system, including the battery terminals and the ground cable at the powerhead.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Solenoid Voltage

12.3 volts into the solenoid is indicative of a bad connection or a weak/discharged battery. By the way -- battery cables have two ends -- make sure BOTH ends are clean and tight.
 

kmarine

Chief Petty Officer
Joined
Nov 5, 2010
Messages
591
Re: Solenoid Voltage

Even though you read 12.3 volts at the soleniod , this I believe is wtihout any load. I recomend a load test with your reading either with a load tester, or see how much of a voltage drop you have when the starter is engsged. Make sure all connectors are clean and tight. You may also remove the starter, take it to a motor shop and see how much current is needed to spin motor fast enough to engauge bendix. They can also see if the bendix is jamed.
 

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: Solenoid Voltage

I would first try Joe Reeves advice. That will narrow down the issue in a heartbeat.
 

Bill3434

Petty Officer 1st Class
Joined
May 29, 2011
Messages
398
Re: Solenoid Voltage

If your battery cables are old you might want to replece them, they could be corroded internally. You contacts in the started could alos be corroded too. Went through a similar issue this past summer. Now have new cables (needed), new solenoid (not needed), cleaned contacts and installed new brushes (needed), new battery (not needed) and lots of time spent cleaning connections from battery to starter several times to include having to do it on the lake, what a pain. Now everything works fine, I have no problems cranking even when the old engine don't want to start. I dissected my old cables once I got my new ones and I was surprised that every single wire was lightly corroded. I installed them and hit the key and I knew that was the main problem, I was so excited I had to go to the lake for a test run.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Solenoid Voltage

Don't guess, TEST the solenoid!!! Connect the + lead from your voltmeter to the big nut on the battery cable side of the solenoid, and connect the - lead of your voltmeter to the big nut on the starter side of the solenoid. Should show battery voltage. Now, turn key to start positon and voltage should drop to zero or close to it. If you have a significant voltage across the solenoid while cranking, there is a resistance across the internal contacts. This is called a voltage drop test and can be used across other components such a battery cables, connections, etc.
 

OSGFII

Cadet
Joined
Dec 11, 2011
Messages
10
Re: Solenoid Voltage

Thanks for all that advise. I finally got to work on my boat a little more, and it looks like there's probably something wrong with the starter.
Thanks again!
 

toddschubert

Chief Petty Officer
Joined
Sep 3, 2011
Messages
504
Re: Solenoid Voltage

Can you rotate the pinion by hand to engage the flywheel? You should be able too. If not may need lube
 
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