Advanced MPEM Help Needed-98GSXL

[sw2789]

Background:
I have been trying to troubleshoot a problem I created by connecting a battery charger to my ski and cranking it right after I purchased it and it immediatly started blowing the 5A fuse. I replaced the MPEM with a used unit off this site and it continues to blow the 5A fuse.

Either I have another bad MPEM which is entirely possible or there is another problem causing the fuse to blow.

I ended up measuring all of the connections and this is what I found is blowing the fuse: The DESS key has 3 wires feeding the terminal. There is a magnet inside the key which connects wires 2-7 and 2-15 as you plug on the key.

I found that 2-7 is Ground wire but the 2-15 wire originates inside the MPEM and I have not determined why grounding this wire blows the fuse. I then cut the 2-15 to separate it from the terminal and did verify the fuse stops blowing but now with the key on there is no activity.

Does anyone know what 2-15 lead does or maybe what some next steps should be to repair the ski? I am thinking this is the location of that diode that people discuss that shorts out when connecting a battery charger.

Other background info:
I tried disconnecting the VTS, magneto, and other items to see if the fuse would stop blowing without success.

Thanks!

 

[Dr Honda]

If you have a power trim... disconnect it from the system, and try it again. When they short out, they can take the MPEM with them... but it sounds like you have a MEPM that's not happy.

Was the member you bought the second MPEM from reputable?

 

[sw2789]

Thanks,

The memeber has a good things said about him here on the forum and buys and sells parts. He has tried to be helpful but wouldn't warrant his electronic parts using the logic that other components could cause the mpem to go bad (which makes sense). I did try disconnecting the VTS at the plug near the engine and then by pulling the fuse but my 5A fuse still blows.

I also found a web site of a tech that shows how to test the MPEM and by using his method this mpem tests good. Unfortulatly I disected my original mpem to try and locate that famous diode that is mentioned on many sites but have not found it on the board as of yet. In the process I broke a couple of tiny components off of the board so comparing future measurements won't be possible.

What wires should be measured for a short to determine if the VTS is bad?

Thanks for your thoughts and help!

 

[Minnetonka4me]

I had one that the VTS worked, but blew the 5a fuse. It threw me for a loop b/c it was a random problem.

Unhook both of the VTS connections...they are a foot after the VTS housing. I had unplugged the Red and black, but there is power running thru the purple in the 6 pin connector. After I unplugged both it quit blowing fuses.

 

[seadooya]

bad rectifiers, can pop the fuse. Unfortunetly, the rectifier for a 951 motor, IS located inside the mpem.

I'm not, "for one", who sells parts without checking if it works, FIRST.

 

[sw2789]

Thanks for both of your suggestions,

Regarding the VTS,
I did disconnect the VTS plug on the side of the ski with 6 terminals and disconnected the VTS fuse but still blows the 5A fuse. Was this a good test or do I need to hunt down the other VTS plug as well?

Regarding the rectifier,
I have read in a couple of locations on the Internet that there maybe an external rectifier kit that can be added to some types of Sea Doos. If I could get my hands on the wiring diagrams that supports the 951 maybe I can determine if that is the problem. I can make a rectifier pretty easliy but I am not sure how to interface it with the existing mpem.

any additional ideas of thoughts?

Thanks!

 

[seadooya]

http://www.seadoosource.com/947rectifierupgrade.html