Bad MPEM?

[challenger54]

1999 Challenger 1800 2x787's

I'm having a problem with the MPEM pwering down randomly...which means of course the boat dies. When this happens there are no beeps when attaching the key..which I just replaced...the guages do not power up when the START button is pressed and the boat will not start or if running dies. which is REALLY embarrassing!

I have thoroughly cleaned the elctrical leads at the battery and the battery cutoff switch. I found 12V power at the upper fuse connector on the MPEM even when the boat refuses to start and guages are dead. MPEM powers back up within a couple minutes (with a audilbe click to signify it's return to life) and boat starts but usually dies after a few minutes. When MPEM dies there is an audible click in the engine compartment. No fuses blown on MPEM, 3 20 amp fuses below battery cuttof switch good, all accesories operate regardless of whether rest of boat is dead or not. That way I can listen to the radio and keep the bilge dry while floating idly in the lake waiting for a tow!

What else can I check? Battery just fully recharged. Engines crank strongly...when they crank! Sure hope it's not the MPEM which is what I'm starting to think. Help please!

 

[RFoster130]

I think it is more of a DESS issue. Why did you replace the lanyard?

 

[challenger54]

I think it is more of a DESS issue. Why did you replace the lanyard?

I changed the key 'cause that's what I thought it was too! Guess what..new lanyard...same old problem! I agree it presents like a DESS problem...but if it is what to check next? I have been told the posts either work or they don't. Wiring harness between post and MPEM? Whew! Where do I start with all that stuff? And why do the guages not power up when a start button is pressed? That function should work whether the key is attached or not..right?