Yamaha 15 HP electric start not starting!

FuzzyGrub said:

Is there an electrical schematic you can post? In my yamaha service manual it is a fold out in tha back.

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MrGiggles said:

Does this outboard have an ignition switch?

Would need to see a wiring diagram to be sure, those start systems are pretty simple. Power usually comes from the main fuse, to the ignition switch, to the start switch, neutral safety switch, and finally to the starter solenoid. Since you have eliminated the solenoid and the neutral switch, my guess is that you're losing power somewhere between the fuse and ignition switch, perhaps between the ignition and the neutral switch.

You can quickly test the integrity of the starter motor, solenoid, and battery by just jumpering the solenoid. Rig up a test lead from battery positive (where the battery positive cable attaches to the solenoid is just fine), unhook the positive coil wire on the solenoid and apply power to it, the starter should engage. If not, you have a poor connection somewhere or bad solenoid.

If it does crank, get a test light or voltmeter and follow that positive solenoid coil wire backwards until you find power again. This is best done with a wiring diagram to "light your way," so to speak.

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Hoppi84 said:

Hopefully you can soon in on it...View attachment 124381View attachment 124382

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1. Use a wire connected directly to 12v and touch it to the small start wire or stud of the solenoid. It should turn over if the solenoid is good and connected properly.
2. If it DOES turn over, the issue is somewhere in the start button circuit, and easy to find. Fuse, frayed wire, bad connector, etc. It's there somewhere.
3. If it DOES NOT turn over, then check the ground wire of the solenoid.
4. Sometimes, a solenoid will be replaced with the ground connected to the wrong stud, and the solenoid won't work. Double-check the wiring

thill said:

Just to be sure, swap out the fuse with a fresh one, and make sure the socket is clean. This will fix these issues occasionally. A partially burned fuse or poor connection may show 12V on a multimeter, but cannot carry enough power to do trip the solenoid.

How did you jump the solenoid? Did you jump across the main lugs, or did you jump 12V directly to the trigger wire or stud? This matters. Here is the sequence I usually follow:

1. Use a wire connected directly to 12v and touch it to the small start wire or stud of the solenoid. It should turn over if the solenoid is good and connected properly.
2. If it DOES turn over, the issue is somewhere in the start button circuit, and easy to find. Fuse, frayed wire, bad connector, etc. It's there somewhere.
3. If it DOES NOT turn over, then check the ground wire of the solenoid.
4. Sometimes, a solenoid will be replaced with the ground connected to the wrong stud, and the solenoid won't work. Double-check the wiring

I hope this is helpful. You WILL find it, probably soon if not already.

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thill said:

Just to be sure, swap out the fuse with a fresh one, and make sure the socket is clean. This will fix these issues occasionally. A partially burned fuse or poor connection may show 12V on a multimeter, but cannot carry enough power to do trip the solenoid.

How did you jump the solenoid? Did you jump across the main lugs, or did you jump 12V directly to the trigger wire or stud? This matters. Here is the sequence I usually follow:

1. Use a wire connected directly to 12v and touch it to the small start wire or stud of the solenoid. It should turn over if the solenoid is good and connected properly.
2. If it DOES turn over, the issue is somewhere in the start button circuit, and easy to find. Fuse, frayed wire, bad connector, etc. It's there somewhere.
3. If it DOES NOT turn over, then check the ground wire of the solenoid.
4. Sometimes, a solenoid will be replaced with the ground connected to the wrong stud, and the solenoid won't work. Double-check the wiring

I hope this is helpful. You WILL find it, probably soon if not already.

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smocosailing said:

I'm going to start this right now. Stay tuned!

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smocosailing said:

I jumped the solenoid by connecting the battery directly to the starter motor ground and the positive wire leaving the solenoid.

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smocosailing said:

I jumped the solenoid by connecting the battery directly to the starter motor ground and the positive wire leaving the solenoid.

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smocosailing said:

Mystery solved!

Well after about 2 weeks of paddling I have finally fixed the problem. Thank you to everyone, I learned so much more about my outboard. Before this I didn't really understand the working of my outboard or what a lot of the major components did. Though this was unpleasant I am actually kind of happy it happened, I now can be more self-sufficient in helping not only myself but other boaters.

So what was it?
I store my starter battery in the bow, to keep it away from the fuel tank. When the boat was originally purchased the battery cable was too short, so I had a 'professional' extend it. He used heatshrink and extended the 10 AWG wire to feed the battery. While working through this current situation I really pulled on the area where the battery feed wire was extended. I head a pop and was greeted by the most corrosion I have ever seen (picture below).

Why didn't I do this before?
When I was diagnosing everything, I was checking voltage and I was getting a good voltage! Though I have been constantly warned about corrosion I didn't think there would be any in connection point of the wire. Looking back this was a super easy solution (and no cost because I have plenty of heat shrink terminals). In my mind, there was no issue with power at the solenoid, starter or anywhere because I was reading 13V. Though I had proper voltage, I didn't have enough amperage to open the solenoid.

Am I upset?
A few days ago, very. I didn't understand how something so new could be so unreliable. Now I know that it wasn't the outboard at all but rather the wire feeding power to the outboard. I've learned so much though that the 2 weeks of me paddling back and forth to shore will soon be forgotten and I get the biggest smile everytime my outboard fires up with a simple push.

Time to dinghy to shore and start the weekend celebrations early.
Cheers everyone!

P.S. the wire is so watertight and well connected now that I'm not concerned about corrosion in the future. But if it does happen, I'll know exactly what to do.

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