Need help tracking down an intermittent engine on/off problem

Tbonus

Seaman Apprentice
Joined
Dec 4, 2004
Messages
34
The motor is a 1998 Johnson 90hp SPL on a 17.5 foot Aquasport. The other day the engine seemed like it was dead. I charged the battery and still nothing. I checked the trim and it worked. I went on to check everything else such as lights and pumps, and they all work. Everything worked except the guages and the starter. I also checked the fuse on the top of the motor. It was fine. I even swapped it with the spare to be sure.<br /><br />I purchased a new ignition key switch and swapped it out with no change. As I was wiggling the shifter assembly and the wires underneath, the guages came to life. I put it all back together and tested - it was dead again. Out of frustration, I hit the area above the key switch with the bottom of my fist. The system came to life.<br /><br />It quit again a little later. I wiggled the shifter arm from side to side, and she came back to life. I actually had her out on Sarasota Bay all day today with no problems.<br /><br />When I got her home for a rinse, she was dead again. I shook the console, and she came to life.<br /><br />I need some help. It must be a loose connection or a switch going bad somewhere. Where to start the search? What would you do?<br /><br />I accidentally posted this under the Mercury Forum the last night.<br /><br />Any assitance is appreciated.
 

CATransplant

Admiral
Joined
Feb 26, 2005
Messages
6,319
Re: Need help tracking down an intermittent engine on/off problem

Sounds like a bad connection or bad switch in the shifter assembly. If it comes and goes when you wiggle the shifter arm, then there's little else it can be.
 

Tbonus

Seaman Apprentice
Joined
Dec 4, 2004
Messages
34
Re: Need help tracking down an intermittent engine on/off problem

Do I need to replace the entire shifter assembly or are there different components that can be replaced?
 

CATransplant

Admiral
Joined
Feb 26, 2005
Messages
6,319
Re: Need help tracking down an intermittent engine on/off problem

I'm sure you can fix the console assembly with individual parts, but I can't really help you there. I'm more of an old motor guy. But the symptoms seem to have narrowed it down to that unit.
 

Tbonus

Seaman Apprentice
Joined
Dec 4, 2004
Messages
34
Re: Need help tracking down an intermittent engine on/off problem

Update on repair - After two trips to the marina, they finally found the short. On the first trip they said they couldn't duplicate the problem.<br /><br />On round two, they put a tech with 35 years of experience on the problem. The excess length of the harness had been stuffed under the flooring and had several bends. One of these bends was almost broken. They replaced about 10 feet of the power wire on the back of the ignition switch and she starts just fine.<br /><br />But now the trim on the handle doesn't work. It works on the motor but not the handle. <br /><br />Just wanted to pass along the fix. Thanks for the replies.
 
Top