MDC 1600 x Malibu Sportster 99

[mjbet91]

Hey guys, 

So heres my situation. Past 2 seasons, gauges have been working intermittently at what seemed like random. 1/2 starts, they would fire up. Recently gauges started working again 100% of the time after dialectic grease on 5 pin and reconnecting everything. And then more recently gauges wont work at all...UNLESS i partially undo the 5 pin connector and tweak it to the right once the boat is already running, then i get gauges as long as my fingers are touching the 5 pin. once i let go, they crap out. 

 

Whats most strange is my running / dash lights have stopped working at the same time, and are also able to run when i tweak the 5 pin. I thought lights where completely seperate from gauges? previously when gauges didnt work, my lights did...

 

Thoughts anyone ? Do the lights have any correlation to the MDC 1600 unit? do they ground out in the same place ? Suggestions? 

[drh]

Looking at the wiring diagram on the last page of the troubleshooting guide I think you're right with the ground:

https://www.themalibucrew.com/_files/misc/medallion.pdf

The gauges are grounded through the 5 pin on the MDC box even though they receive 12v switched from the the nav light switch.

Edited August 19, 2020 by drh

[Eagleboy99]

Sounds like a ground issue ot me.  Do you have a buss bar somewhere for grounding?