MPEM Issue - Yellow/Red Wire to Starter Relay Always Has 12V - Transistor?

[Charlie_gtx]

Greetings from Spain!

Hi everyone!
I'm troubleshooting my 1997 Sea-Doo GTX. It runs great, but today after the fourth or fifth start of the day, the starter motor has stuck engaged. I have checked the relay and the yellow/red wire to the starter relay from the MPEM output is constantly outputting 12V, even without the D.E.S.S. key connected.

This started spontaneously, and I suspect a faulty transistor in the MPEM. Has anyone experienced this issue? Does anyone know which transistor in the MPEM controls the yellow/red wire output to the starter relay? I know there is a xray which shows the board, but i can't see the trace from the cable to any component

Any help with diagnosing or fixing this would be greatly appreciated! Thanks!

 

[artr]

While it does sound like a MPEM fault I would check the following:
Disconnect the yellow/red strip wire from the base of the start solenoid and check that the wire still has 12V on it.
If it does then inspect that wire back to the MPEM pin and check that it is not short somehow to a 12V line. There are a couple of connectors along the way and that line is right next to a 12V line. There could be corrosion between those lines at the connectors. Clean up the connectors with contact cleaner or alcohol and a tooth brush.
If those 2 things check out then it probably is the MPEM and the only surgery on the MPEM I have read about deal with diode replacement when fuses blow.

 

[Charlie_gtx]

Thanks for the help! I disconnected the yellow/red wire from the starter solenoid, and it still shows 12.4V. I also checked the wiring and connectors for shorts or corrosion, and everything looks clean. I have 12.4v right at the first connector inside the mpem grey box.

If i dont find a solution, I'm thinking about installing a pushbutton on that line, so I can use the ski for the rest of the season and change the Mpem nect year.

 

[artr]

Check if the start/stop button has failed and is constantly shorted or the wire that runs from it to the MPEM is constantly grounded.

 

[tobytd]

Is the hot always there and the MPEM completes the circuit by making the ground?

 

[Charlie_gtx]

No, the ground is the same as the ignition coil, the hot is an output of the mpem and is always "on".

It is not the start stop button, as it does it without the dess key.

To start it, i put the dess key, push once the start stop button and then join the yellow/red cable that i previously disconected.

 

[Charlie_gtx]

The mpem has finally died, it doesnt recognize the key, the info doesnt turn off after 30 sec like usually, i have no spark and no beeps. Also the 12v to the starter solenoid is always on.

Now i need a new mpem and they are hard to find here.

Regards, Carlos.