Weird starting issue: Usually it turns over and starts but not always...

Twhjelmgren28

Petty Officer 3rd Class
Joined
May 31, 2016
Messages
85
I have a 120hp Mercruiser i/o. I kept both batteries (deep cycle and starting batter) on a trickle charge throughout winter. I should mention that I also installed an ACR and a dual circuit battery switch last summer.

For some reason, sometimes my boat will turn over and run just fine and other times, when I turn the key I get absolutely nothing; no sound, no click - the only thing is my gauges set themselves, which makes sense.

For example: I could start it five times in a row and then the sixth and seventh time nothing happens when I turn the key. On the eighth try it will turnover and start.

I plan on cleaning all the connections at the ignition switch and the starter tonight after work. My battery connections are very clean and tight already - also, the ACR shows that both batteries are combined when they are over 12.6v so I'm certain the battery has enough juice (also nothing changes when I switch to combine both batteries). The only other thing I've noticed is sometimes after I turn the ignition switch, it kind of gets gummed up at the "start" spot and I almost have to help it back to the "on" spot.

My thoughts are:
1. Bad/corroded connection
2. Bad starter
3. Bad ignition switch

Any other suggestions for what I should look into are greatly appreciated - for now, I'll just work on cleaning those connections.

Thanks!
 
Last edited:

alldodge

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Mar 8, 2009
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42,538
The only other thing I've noticed is sometimes after I turn the ignition switch, it kind of gets gummed up at the "start" spot and I almost have to help it back to the "on" spot.

Sounds like a bad switch to me, and even if that isn't the issue I would replace it
 

Bondo

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Apr 17, 2002
Messages
71,082
My thoughts are:
1. Bad/corroded connection
2. Bad starter
3. Bad ignition switch

Ayuh,..... I'd start at #1, 'n go to #3,..... 2 is possible, but #1 is 'bout maintenance,....

A test light will help with testin' the switch,....
 

kmarine

Chief Petty Officer
Joined
Nov 5, 2010
Messages
591
Is the solenoid clicking are the connections clean with a good ground. I replace lots of these for people. About 1/3 of the starters replaced have only solenoid issues.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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50,230
I would go with a bad connection, or a bad pilot relay
 

Twhjelmgren28

Petty Officer 3rd Class
Joined
May 31, 2016
Messages
85
I appreciate all the responses. Thanks!

I guess I will start with #1 (maintenance/cheapest) and for sure replace the ignition switch, as AllDodge stated - it is getting kind of getting gummed up, as I mentioned.

Then, I'll start looking into starter and/or pilot relay as mentioned.

Is the solenoid clicking are the connections clean with a good ground. I replace lots of these for people. About 1/3 of the starters replaced have only solenoid issues.

I will be cleaning all connections...The solenoid is NOT clicking when I turn the key. There is absolutely no sound whatsoever...

Thanks again and I'll keep you posted.
 
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