MPEM Pulls 12.6 off battery at all times. Is this normal?

[Freight53]

My 1998 Seadoo GSX Limited drains the battery without the DESS key installed. I've hook up a voltage meter between the negative battery cable and the negative battery post, it shows 12.6 volts with no DESS key installed. If I remove the MPEM fuse the voltage drops to zero... Any reason or thoughts why my MPEM is pulling that voltage at all times? Is that normal? Also, the display is not on unless the DESS key is installed.

[K447]

'Pulling voltage'?

Check for current draw, not voltage, using the same measurement method, between battery post and battery cable.

There may be a tiny (very small milliamperes) current draw, which would not create a significant battery drain problem.

Hundreds of mA is no good, causes rapid battery drain.

[Freight53]

Yes, its a rapid battery drain. Installed a fully charged battery, hooked up as prescribed on my white gsx. Came back to her this am and she had a dead battery. Even had the VTS unplugged.

Installed the same mpem and a good battery on my other 1998 gsx (red) and let it sit over night. Came back to a good battery.

As said before, when I have my meter between the negative battery cable and post, it draws 12. When I pull the MPEM fuse is drops to 0.01... or how it should be.

[nmpeter]

it's normal to have some ignignifcant ( short term) draw on any older seadoo system. The mpem is always looking for a key event

this is well documented which is why its often advised to disconnect the battery at th eend of the season.

this has been updated in the last few years so now a punch of the start button is required to wake up the emm then the post will recognize the key

I would disconnect the post and see what happens

the post often fails in the open condition, but if your switch is tuck closed, it could run down the battery in a day or two.

[Redbone]

You dont "draw" voltage, you draw amps... yes the Mpem will always have voltage going to it, you are basically checking the battery at that point.

Turn your meter to amps, adjust the probes accordingly and check inline on the positive terminal. You shouldn't have any more than .02 amperes

Start unplugging stuff until the draw does away. Free tip, start with the dess post.

Just unplugging the mpem or ecu basically cuts everything. That should be last resort.

[nmpeter]

yeah what we said

[Freight53]

Thank you all for the advise and after work today I will take this advise and explore more into it. More to come...

[Sanfish]

I know on the '99-up the voltage regulator is in the actual ECU, but IIRC, on a 98 its external (which is a better design). So I would start by unplugging the voltage regulator and see if that fixes issue. I bet thats it.

[Freight53]

Here is something that will tickly your noodle.(Maybe)…I’ve tracked down what I feel is the amp draw.From the MPEM going to the 3-phase stator,one of the three wires has 12v.Ithought the 3-phase stator put out voltage to the MPEM, not the other wayaround.I chased the three wires fromthe stator plug on the front case of the motor to the connection at the MPEM,all have good continuity; yellow, yellow, yellow to 2-26, 2-25, 2-24 per wire schematic.If I am correct, MPEM male tab 2-26, 2-25,and 2-24 should not have power.Pleaseadvise.

[Freight53]

Here’s more, just installed the MEPM in my red GSX andperformed the same test…No voltage in2-24, 2-25, and 2-26.Performed asadvertised.Something in the wiring inmy white GSX is causing voltage to be where its shouldn’t be.