Johnson 15, ran great yesterday, won't turn over today!

[compusolver]

Strange problem - '79 Johnson 15hp (Model: 15EL79E) always ran great, starts right up, etc. Was starting to sputter at top end, so I replaced the fuel pump, but now when I hit the starter button, it won't turn over, or even make a sound. I may not be tracing the electric circuit correctly, because although I'm getting voltage at the starter (when I press the Start button), I get the same voltage even when I put it in gear. The only wiring diagram I can find is for slightly older models and shows the big red wire going first to a neutral switch, then to the starter. But my red wire goes straight to the starter, with a second wire going to a row of wires on the other side of the motor. I'm thinking I may have accidentally done something to mess with the neutral safety stuff, but I have no idea what that is and I can't find any mention of neutral safety for this model (which I think is basically the same as the 10hp). I've been to http://www.leeroysramblings.com/Johnson 9.9_15.htm, etc.

Can anyone suggest anything that might put me on the right track?

Also - I've disconnected the shorting switch to eliminate possibility of a problem there.

 

[kbait]

Jump starter motor directly from known-good battery. If motor turns over, you have a wiring/connection problem.
Good luck!

 

[AlTn]

if this problem surfaced right after you replaced the fuel pump, retrace your steps and determine if you inadvertently knocked something out of adjustment, or if you had to remove some wires to get to the fuel pump, are they reconnected properly and if a ground, is the ground clean and tight?

 

[compusolver]

AITn, U may be onto something. Manual says neutral safety is next to fuel pump, but no explanation of how it works.

 

[compusolver]

My neutral safety switch has no wire connected to it and no insulation between the two plates. Apparently, previous owner took this out of the circuit and ran wire straight to starter. Removed starter & tested ok. Will start over tomorrow, retest switch, then focus on rectifier??

 

[racerone]

The rectifier is part of the battery charging circuit and not the starting / cranking circuit.

 

[compusolver]

Thanks, racerone! That will save me from screwing up something else! if the switch checks out, can you think of any other reason the starter isn't turning over? (I removed the starter today & hotwired it - it turned fine).

 

[fireman57]

Have you checked your solenoid? try jumping across it with a screwdriver and see if it cranks..

 

[gm280]

Since this sounds like it just stopped work suddenly, have you checked the inline fuse? Because that fuse will stop it from starting if blown. Also, rewire you neutral safety switch back in. That protects anybody from starting the engine in any gear. And that can lead to somebody getting seriously hurt. So rewire the neutral switch back. If that neutral switch isn't working, buy a new one and install. While you may understand it has been circumvented, other will not know that...

 

[sumocomputers]

Had the same problem with my Johnson 89 70. It turned out the 20amp fuse AND the solenoid were bad. I suspect when the solenoid died it took the fuse with it.

The Service Manual had very easy instructions on testing the solenoid, and once confirmed bad, a new aftermarket one was $20. It was easier to find than that damn small 20amp fuse though!

 

[kbait]

No solenoid on that motor. The start button transfers all the amps to the starter.

 

[racerone]

A fuse on this motor ?????

 

[compusolver]

Thanks everyone, for all the advice. No solenoid on this motor. Doesn't seem to be any fuse either. I'm thinking that somehow the neutral safety is shunting the circuit, preventing starter and ignition from getting juice. Can't seem to find any photos or good text on this neutral safety switch. On my motor, it's just two pieces of metal that get separated or not at the far end, depending on position of shift lever. Problem is, they are in solid contact where they bolt to the motor and no wire connects to them - which means they have no useful electrical purpose that I can think of.

I promise to update when I finally bring this to a conclusion. Meanwhile, I'll be checking back here each day for ideas. Thanks again.

 

[racerone]

Maybe someone has taken the nuetral safety off.-----------Where do the wires run ? ----Does the wire from the starter run straight to the start switch ?

 

[gm280]

I re-read you original post and this last one as well. Sounds like the push switch could be an issue. Being how that one switch carries all the current to the starter, it takes more of an electrical/current beating then an engine with a starter solenoid. So it could be fried inside. To test this, jumper straight to the starter from the battery and see if that spins it over. If it does, then replace that push switch. If it doesn't, remove the starter and test it. By the way that switch part number is 0389856. Do let us know what you find as the problem either way. That way others having the same problems can read you thread and learn...

 

[compusolver]

Wire does run straight from switch to starter. My tester shows that the switch seems to be working. Have removed starter & hotwired - it turns fine.

 

[compusolver]

Well, this is embarrassing, but the problem wasn't connected to the neutral safety after all. Both battery cables had been butt-connected, then covered with heat-shrink. Apparently they'd pulled loose, but for awhile, had just enough of a connection to light my test light, but not turn the starter. Thankfully, after I moved the battery a bit, the connection broke altogether, allowing me to track down the problem.

Thanks to everyone for your time and assistance!

 

[AlTn]

glad you found it and thanks for posting the solution

 

[sumocomputers]

I have had to rip out every single wire from the boat I bought. This is after I kept trying to track down gremlins, and turns out there were butt splice upon butt splice upon wire nuts, upon...

None of which were sealed in any way. By the looks of it, I am guessing there were at least 5 owners since 1980...

Anyway, glad you found it.

 

[glust]

I have had to rip out every single wire from the boat I bought. This is after I kept trying to track down gremlins, and turns out there were butt splice upon butt splice upon wire nuts, upon...

None of which were sealed in any way. By the looks of it, I am guessing there were at least 5 owners since 1980...

Anyway, glad you found it.

Amen. Once I run into a project that has the all too indicating electrical tape on it I am tempted to dig out a new wiring harness and start all over. On my pontoon boat I removed all wiring from the helm and ran everything new. You can spend an awful lot of good boating weather with a multimeter in your hand instead of an icy cold beverage.