1 reply to this topic

[jennkent5454]

here comes a complicated question-
I have a 1998 seadoo challenger 1800, It had and electrical short and I believe it shorted out the MPEM. I had a seadoo mechanic remove the original MPEM and replace it with 2 separate MPEMs from 1996 SPXs.
The jet boat runs fine. the 3 issues I have are as follows:
1. both of the tachs and the speedometer do not work. they have power because they light up, the mechanic says the were all three shorted out by the above mentioned electrical problem. is there a way to test the gauges? is there another gauge out there from another PWC that can be swapped out for these that is cheaper than the original?
2. the deck lights do not work, I dont think these run off/through the MPEM any how, what would be the easiest way to test these lights to see if they didn't get wired back correctly or at all?
3. with having two MPEMs now, he had to add another DESS & lanyard, which means there are now 2 DESS post. is there a way to wire both DESS posts into one ? and make it where any lanyard will work?

[BigWayne]

First, lets split your questions into two seperate items, as the potential solutions to them will be different.

The deck lights are controlled through the MPEM, but they can be easily bypassed by re-wiring the supply and return lines through the dash switch and an external fuse. Simple solution that shouldn't take too much time.

Now for the second issue. The spedo will only receive valid engine speed from the MPEM. Since you rewired the one OEM MPEM into two individual units, you will have to locate and connect the spedo connections to the MPEM.

I will attach the wiring schematic for reference.

Wiring for the seperare MPEMS is on page 45 and 46 of the appropriate documents.

I'll locate the witing diagram for the single MPEM shortly.

Attached Files

•  seperate mpem wiring diagram.pdf   7.36MB   5 downloads