Keep blowing my starter solenoid up.

rpatton

Petty Officer 1st Class
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Feb 17, 2011
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256
On my 2.5 my starter solenoid keep going bad. I replace it and it will start up and run great. Go on the water and after 5 minutes running the motor dies and will not crank with the key unless I jump the large terminals then it will crank but no start. Replace the solenoid and it’s fine . I hate being towed in. Any ideas??
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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got a picture of the wiring to your pilot relay? pretty sure the wiring needs some TLC.
 

rpatton

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Feb 17, 2011
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got a picture of the wiring to your pilot relay? pretty sure the wiring needs some TLC.
Thanks for the reply, guys. When I get home Ill snap a picture or two. does the solenoid need to be grounded thru the solenoid mounting plate? The person that had it prior to me actually left the old solenoid mounted completely disconnected and then mounted the new one to one of the terminals on the old solenoid. Very hinky I know. But it does not look too easy to remove and mount the correct way. Looks like the whole throttle plate needs to be removed to do so. I did notice a small gauge black wire with a metal terminal to mount somewhere coming out of the bundle with the starter wires leading to the solenoid. Should that be grounded somewhere?
 

rpatton

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Feb 17, 2011
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update on my issue. after doing some checking with a voltmeter and test light I found that my alternator is putting out to the ignition switch 16.8 volts just off of idle on the hose. Way to high. Thinking this is what's burning up the contacts in my solenoid. Thoughts?
 

Grub54891

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Jun 17, 2012
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Depends on the condition of the battery, have you had it tested? If it’s weak the alternator will try to keep up and you will see higher voltage. And after y start it, it will read higher as the alternator is filling it back up. After running for 1/2 hour it should level out. The solenoid the way you have it mounted may work but I’m not sure if that particular one would be bolted to the mount correctly as it may need to be grounded. The way you have it will not ground it at all..
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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if the purple wire reference to the alternator sense pin calls for more juice, that alternator will try to make that sense pin voltage go above 13.8.

as stated, depends on the battery and condition of the wiring.
 

rpatton

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Feb 17, 2011
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Battery load tested fine and full .Brand new cables also. I forgot to add that the circuit breaker on the dash was tripped. I reset it and it fired right up no issue. I may be wrong but if the alt is putting too much out wouldn't it trip the breaker?
 

dingbat

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Nov 20, 2001
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Battery load tested fine and full .Brand new cables also. I forgot to add that the circuit breaker on the dash was tripped. I reset it and it fired right up no issue. I may be wrong but if the alt is putting too much out wouldn't it trip the breaker?
Circuit breakers trip on current, not voltage.
Have you checked to see if the starter is on the way out?
 

kd4pbs

Seaman Apprentice
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Mar 5, 2012
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36
Higher voltage will cause most accessories to draw higher current.
Scott hit the nail on the head - you've got a connection someplace which has high resistance indicated by the fact your voltage regulator's reference (sense) line is apparently seeing a lower voltage than normal due to resistance in that circuit. That lower sense voltage is causing the regulator to drive the alternator to a higher voltage than it should be. 16.8V is way too much for a system which should see at most 14.4ish max.
 

sdowney717

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Jul 16, 2011
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update on my issue. after doing some checking with a voltmeter and test light I found that my alternator is putting out to the ignition switch 16.8 volts just off of idle on the hose. Way to high. Thinking this is what's burning up the contacts in my solenoid. Thoughts?
Verify the alternator has a good ground to the engine block, check all wiring with an ohmmeter.
Check all grounds. Helped a guy with an alternator, and he had no connection of the iron alternator bracket to the block, due to so much rust, means the alternator had no connection and could not charge anything. We verified that by attaching a separate ground wire from alternator to the engine, and then alternator worked fine.
 
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