I have a 2004 Maristar and am having the following issues, which all showed up at teh same time?
1) SPEEDO INOP
2) CHECK ENGINE LIGHT COMES ON, AND AUDIBLE ALARMS SOUNDS FOR 2 MINUTES.
3) RADIO INOP
My votgage gage is only reading 10.5v, even thou i just replaced the batter. I understand that the system in teh boat will shut down the radio if and when the voltage guage reads below 11.5v. This is to ensure you hear the low battery alarm that sounds. I am thinking the issue is the MMDC, but wanted to get your thoughts? And any way , short of replacing it, to test the MMDC?