98 Spx starter solenoid stuck closed. (It’s Not the solenoid)

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it has a 787 and the moment I touch the ground for the starter to the battery it starts turning over. No key or anything. I rebuilt the starter at the beginning of the season. And it has a fresh battery that’s a month old.

I’ve tried 2 different solenoids 1 used and 1 brand new and the brand new one does the same thing and the used one wouldn’t do anything.

What am I missing? Do I need to look at the starter it’s self or is there somthing im over looking or am I just having bad luck with solenoids.
 
It started happening when I was riding it. I shut it down and could hear the starter spinning away in the engine compartment, so I disconnected the battery and swam it back to my dock.
 
if you have ruled out a sticking selenoid,,,and startstop switch,,,then it could be the computer playing tricks on you?
 
Disconnected the small wire (maybe yellow/red) to the solenoid. If the solenoid continue to conduct then it is bad. If it stops conducting then try pulling the 15amp fuse in the MPEM. That definitely should kill power to the solenoid activation circuit. Try putting the 15 amp fuse back and pull the 5 amp fuse that powers the MPEM. What happens?
 
Disconnected the small wire (maybe yellow/red) to the solenoid. If the solenoid continue to conduct then it is bad. If it stops conducting then try pulling the 15amp fuse in the MPEM. That definitely should kill power to the solenoid activation circuit. Try putting the 15 amp fuse back and pull the 5 amp fuse that powers the MPEM. What happens?
So when I disconnect the yellow/red wire and the black one it stops power going to the starter but when I put the small ground wire on the solenoid clicks really fast.

When I disconnected the 15amp fuse in the mpem it was the same thing.

When I pulled the 5 amp nothing happened when I touched ether grounds to the battery.
 
Let me make sure I understand. You disconnected the yellow/red and black wires from the solenoid. That deactivated the solenoid and the starter stopped. Correct? Then you reconnected the black wire (ground wire) (but not the yellow/red wire) and the solenoid acvtivated? I think I must misunderstand because the solenoid will not activate without having the yellow/red hot wire attached. So, I am assuming that the solenoid is activated when both wires are attached, not just the black wire. Correct? Now to the MPEM. With both wires connected to the solenoid you removed the 15 amp fuse and the solenoid was still activated. Then you removed the 5 amp fuse that powers the MPEM and the solenoid deactivated. Correct? If so, then this says there is a short in the MPEM - bad news. What year/model Seadoo? I will look at circuit diagram and see if there is any work around. Jim
 
One last thing. You said when you connected the ground (assuming you mean the black wire) that the solenoid clicked really fast. What do you mean. Did it close really fast (as expected) or did it chatter (on and off really fast)?
 
Let me make sure I understand. You disconnected the yellow/red and black wires from the solenoid. That deactivated the solenoid and the starter stopped. Correct? Then you reconnected the black wire (ground wire) (but not the yellow/red wire) and the solenoid acvtivated? I think I must misunderstand because the solenoid will not activate without having the yellow/red hot wire attached. So, I am assuming that the solenoid is activated when both wires are attached, not just the black wire. Correct? Now to the MPEM. With both wires connected to the solenoid you removed the 15 amp fuse and the solenoid was still activated. Then you removed the 5 amp fuse that powers the MPEM and the solenoid deactivated. Correct? If so, then this says there is a short in the MPEM - bad news. What year/model Seadoo? I will look at circuit diagram and see if there is any work around. Jim
It’s a 98 Spx.
So I don’t have the 2 ground cables on the battery. I take the big ground wire that goes to the starter and touch it to the negative thermal on the battery and the starter will immediately start spinning. Like I don’t have the key on it or anything.

The yellow/red wire and black that plug into the front of the solenoid is what I was talking about unplugging. Than I took the big ground wire that goes from the starter to the battery and touched it to the negative terminal and it sparked but the starter wouldn’t spin at all.

Here’s a video showing the basic problem.
 
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I attached a wiring diagram for your Seadoo with some of the wiring highlighted. This shows the two red wires, one from the battery to the solenoid and the other from the solenoid to the starter. It also shows the black wired from the battery to the starter. If you touch the heavy black wire to the battery and the starter turns then the only way that can happen is for the solenoid to be activated. It is either faulty or activated by current flowing through the yellow red wire (highlighted as yellow). Can you disconnect that wire from the solenoid? If so, does the starter still start when touching the heavy black wire to the battery? If the starter does not turn then the solenoid is deactivated and the problem is due to current being on the yellow red wire when it is not supposed to be there. You removed the 5amp fuse from the MPEM and that kept the current from being on the yellow red wire. Is that correct? If so, then I suggest disconnecting the starter button. There is a connector on the yellow-red wire from the starter switch (highlighted in blue here and the connector is circled). Disconnect that and see if power is still getting to the yellow red wire. If so, then you have an MPEM issue. I have never tried to open one of those smaller units so I have no advice other than replacing it. Sorry I can not be of more help. Jim
 

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I attached a wiring diagram for your Seadoo with some of the wiring highlighted. This shows the two red wires, one from the battery to the solenoid and the other from the solenoid to the starter. It also shows the black wired from the battery to the starter. If you touch the heavy black wire to the battery and the starter turns then the only way that can happen is for the solenoid to be activated. It is either faulty or activated by current flowing through the yellow red wire (highlighted as yellow). Can you disconnect that wire from the solenoid? If so, does the starter still start when touching the heavy black wire to the battery? If the starter does not turn then the solenoid is deactivated and the problem is due to current being on the yellow red wire when it is not supposed to be there. You removed the 5amp fuse from the MPEM and that kept the current from being on the yellow red wire. Is that correct? If so, then I suggest disconnecting the starter button. There is a connector on the yellow-red wire from the starter switch (highlighted in blue here and the connector is circled). Disconnect that and see if power is still getting to the yellow red wire. If so, then you have an MPEM issue. I have never tried to open one of those smaller units so I have no advice other than replacing it. Sorry I can not be of more help. Jim
This is incredible helpful. I just got it off the loft on Sunday and just got it back to my house today so I’ll be able to work on it easier and more often now. Thank you
 
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The other day I had unplugged the stator to make getting mpem apart easier. Hopefully this makes more sense to you.


when I unplug the stator with all fuses in and touch the big ground wire to the battery the starter doesn’t spin. But when I touch the little one to the battery the solenoid clicks.

When I pulled the 15 amp fuse out of the mpem with the statue plugged in touching the big wire to ground spun the starter and touching the little one to ground made the solenoid click.

When I pulled the 5 amp fuse out it killed all power.

When I tested the starter button I got open loop.

Also when I touch the small wire to ground the trim is working but the gauges aren’t.
I’m thinking the mpem is fried and since this is a freshly rebuilt engine from a local guy. So Idn if the stator is a cheap one and fried the mpem.

I ran out of day light at that point.
 
If you check the diagram I sent closely you will see that the small black wire on the battery grounds the solenoid activation coil. If there is current flowing to the solenoid via the yellow/red wire then touching the small black wire to the battery will activate the solenoid. This is to be expected. However, your problem is why is current flowing via the yellow/red wire when it shouldn't be? It seems the only explanation is a faulty MPEM. I have never tried to open one of the smaller MPEM units but I suppose it should be no different than any of the other devices that Seadoo pots with that black material. I have a philosophy -- if its broke then try to fix it - there is only an upside because if you succeed then great. Otherwise it is still broke. I would use a heat gun to slowly carve that black potting material away and look for large diodes or large transistors. The diodes are pretty easy to replace. Power transistors are more difficult since they are through the pcb. Good luck Jim
 
If you check the diagram I sent closely you will see that the small black wire on the battery grounds the solenoid activation coil. If there is current flowing to the solenoid via the yellow/red wire then touching the small black wire to the battery will activate the solenoid. This is to be expected. However, your problem is why is current flowing via the yellow/red wire when it shouldn't be? It seems the only explanation is a faulty MPEM. I have never tried to open one of the smaller MPEM units but I suppose it should be no different than any of the other devices that Seadoo pots with that black material. I have a philosophy -- if its broke then try to fix it - there is only an upside because if you succeed then great. Otherwise it is still broke. I would use a heat gun to slowly carve that black potting material away and look for large diodes or large transistors. The diodes are pretty easy to replace. Power transistors are more difficult since they are through the pcb. Good luck Jim
Thank you for your help
 
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