Gauges not working

[Grant]

The gauges in my '01 Sunsetter LXi aren't working. Most of the time all of the gauges are dead, but sometimes they come to life and work fine. At first, I could make them come on by wiggling the 5-pin connector on the bottom of the MDC. The connector and pins LOOK good and corrosion free. I put in a brand new MDC and it didn't change anything. Any suggestions on where to look next would be greatly appreciated!!

[cbmalibu98]

Grant,

I had kind of the same problem with my 98. I did what you did and replaced the 5-pin connector and got nowhere. I got to messing around with the connection and in one position everything worked. So I taped everything together in that position and it has been working fine ever since. That was 3-years ago. I am sure you would probally like a more cut and dry fix, but that is what happened in my situation. I am sure you will get a lot of other ideas.

Good Luck

CB

[wienrdog]

Try wiggling the 'cannon plug' on the rear starboard side of the engine. Big plug with a hose clamp on it. Worked for me with some intermittent gauge failures last summer.

Will likely need to do the mark it, pull it apart & clean/spread connections & reconnect the marks trick before too long. Just moving it a bit seemed to do the trick last year.

[ramboat]

Does anyone know where I can purchase the 5-pin and 18-pin connectors for the MDC-1600?

Thanks,

Ken

[Foxbat]

Does anyone know where I can purchase the 5-pin and 18-pin connectors for the MDC-1600?

Thanks,

Ken

I just saw the same problem on my 2001 Sunscape (23LSV). Fired the boat up with a Fake Lake and everything was working fine, then the guages stopped working. One thing though the gauges are stuck on the last value they were reading (i.e, temp at 160, RPM at 700, etc.). Is this the same symptoms that you guys are seeing?

PS: not sure where to purchase the 5 and 18 pin connectors.

I have one question, where does the MDC reside. Is it under the dash?

Edited July 13, 2011 by Foxbat

[70mercury]

I have a 2002 Sportster and my gauges have been doing that same thing for a year now and I have just lived with it. I didnt know where to start and didnt want to spend alot of money getting it fixed at the dealer. The worst part has been not knowing how much gas I had. But I always tried to keep it full anyway. This is the first time I have had any real problems, most of it has been regular maintenance stuff. My question is.... What is the MDC and what does it do? On my 02 sportster where is it located? Thanx in advance for your knowledge and help! -Brian

[Pistol Pete]

This is the MDC. (NOTE: this is not the exact model for your boat, you'd have to look it up)

They are mounted under the dash behind the steering wheel. Easy to find b/c it's so freakin' big and has 2 rubber hoses going to it. It takes in all the engine sensors input and speed from the pitots and converts those signals into something that the gauges run off of.

[70mercury]

Wow Pete Thank you for all that. That book looks like it will be well worth it also.

[Pistol Pete]

Wow Pete Thank you for all that. That book looks like it will be well worth it also.

I'm glad you noticed the book.

Yeah, I've been on here for a few weeks now.

Forgot to mention that it seems to me that it's common for the MDC to fail in circa 2000 boats.

Biggest problem is water coming up the pitot tubes and entering the MDC. This is instant death.

[Foxbat]

I called a dealer today and talked to the parts man (Central Valley Marine in Campbell CA). I explained the symptoms and he seemed to be quite aware of this problem (Medallion MDC). He said that they (service dept.) can hook it up to a computer and check it out and sometimes this just resets the module and you are good to go. He also suggested that I disconnect the battery for a couple of minutes and reconnect to see if this clears this up. I'll try that this evening along with disconnecting the module at the dash (which is essentially the same thing I would believe). I'll post the results.

PS: I went ahead and scheduled an appointment with these guys for Aug 5 (soonest I can get in), just hedging my bets on this.

[Foxbat]

Oh yea, thanks for the link Pete. That helps alot.

[Ski Squirrel]

Foxbat, I am experiencing similar issues with my 2001 Response, which has the Medallion 1st Mate MMDC. Specfically, my speedo analog guage is fixed on 24 mph and won't move (see recent post Speedometer Not Working). My LCD message center will read the port side speed, but the starboard side does not register. Curious to know what you disagnose, so please do post your find and fix results.

[msuwaterski]

I just saw the same problem on my 2001 Sunscape (23LSV). Fired the boat up with a Fake Lake and everything was working fine, then the guages stopped working. One thing though the gauges are stuck on the last value they were reading (i.e, temp at 160, RPM at 700, etc.). Is this the same symptoms that you guys are seeing?

PS: not sure where to purchase the 5 and 18 pin connectors.

I have one question, where does the MDC reside. Is it under the dash?

Interesting, I am having the exact same issue with my '01 SSlxi. Only my issue is with the RPM's gauge only. It froze on Saturday at 2100 and has been there since. Everything else is working.

[wienrdog]

One thing that helped when mine used to freeze was pulling the lanyard. Not sure why, but it did seem to reset the MDC if one gauge was stuck. Here is another good reference:

MDC Troubleshooting reference - EpicMarine.com

[Ski Squirrel]

One thing that helped when mine used to freeze was pulling the lanyard. Not sure why, but it did seem to reset the MDC if one gauge was stuck. Here is another good reference:

MDC Troubleshooting reference - EpicMarine.com

Wienrdog, what does "pulling the lanyard" mean? Thanks for pointing out the troubleshooting guide, the wire schematic should come in handy.

[msuwaterski]

So I have pulled the lanyard, wiggled the wires in the back, checked all connections for corrosion/secure fit, and still have a stuck RPM. I have not diconnected the battery so I will try that. Any other ideas out there or is my goose cooked on the MDC?

[wienrdog]

Pulling the red lanyard/kill switch clip. It seems to cut power to the MDC in a different way than cutting off the ignition.

I had my tack freeze at idle a few times this weekend, but fortunately it came back after just turning off & restarting with the ignition.

[Grant]

I tried the suggestions with the cannon plug and it worked like a charm! All I did was pull out the plug and put it back in and all the gauges came back to life (except the speedo that seems to have some other problem). I would definitely recommend anyone to start with unplugging and reinserting the cannon plug if they are having any type of electronic issues.

[response02]

The LCD will not display anything on my 2002 malibu, has anyone heard of LCD problems

[paxcam]

So somebody tell me how to disconnect the cannon plug. I've taken the hose clamp off, but for the life of me, it won't budge. Does it pull straight out, or is there a twist?

I've tried to pry to rubber sheathing back, but that didn't help, either.

Thanks for any help on the subject. I followed the procedure to check my MDC and I'm, 99% sure my computer has fritzed. But want to make sure the wiring harness is getting good signal from the cannon plug as well.