Author Topic: Medallion Gauges  (Read 3154 times)

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Offline jreggers

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  • Boat Make/Model/Year: American Skier Volante - 1999
Medallion Gauges
« on: July 22, 2019, 08:34:57 AM »
I own a 1999 American Skier Volante. My parents bought the boat from the original owners 10 years ago and I purchased it from them 2 years ago. The original owners maintained the boat pretty well having professionals do all the work. I have done the general maintenance since then, but sometimes it's clear I only know enough to be dangerous. Believe it or not I just found this forum this summer as I was trying to fix an intermittent starting issue. The site helped me solve that problem so thanks to everyone who has posted their knowledge, but yesterday at the lake a new problem emerged. My medallion gauges stopped working.

About 3 years ago the 4 cluster gauge that has fuel level, engine temp, oil pressure and voltmeter started working a little funny. Every so often something wouldn't show up and it was never consistent. Maybe I wouldn't get a reading on the fuel, next time it was oil pressure, next it was engine temp, etc. This was few and far between, and every time it happened, if I giggled the wires at the connection to the gauge it would reset and be fine. I never had the time to look too far into it, so I just dealt with it.

This year it has been more persistent and has taken a few tries to get the gauges to reset. Then yesterday, I started the boat and everything worked fine. About 5 minutes into our first run, I lost all gauges. No readings from anything, Speedos, tach, fuel, oil, etc. Not even the hour meter came on. I looked at and wiggled all connections. I pulled connectors out and re-seated them. Nothing fixed it. So instead of a lot of skiing, I did some testing.

As I ran the boat, I saw the gauges try to reset every 30 seconds or so. If you have medallion gauges you're familiar with the needles vibrating at the bottom during a reset or startup. I found that I would get the speedos and tach to work at sustained slower speeds, maybe up to 20mph. Then after running long enough I started to get intermittent readings from the 4 cluster gauge. All gauges still tried to reset every 30 seconds at this point. After enough driving I had almost normal function from the gauges.

I found this site that has troubleshooting suggestions for the medallion system. http://www.epicmarine.com/docs/MDCtrouble.PDF
Unfortunately I found it after I got home yesterday and I have not had time to run the boat on the trailer to try the troubleshooting suggestions.

My guess is that the 4 cluster gauge is defunct and if I unplug it the rest will run fine, but I haven't tested that yet.

I never knew that the medallion system needed to be drained as a part of the winterizing process. I have winterized the boat myself for the last 10 years and for the last 3 it has been Missouri where we do get freezing temps. It spent two of those winters in Missouri outside all winter and I've never touched those MDC connections but the gauges have always been working as described above. Last winter it was stored in an indoor, climate controlled facility, but I still did the normal winterizing process (again, without knowing I needed to do something with the MDC). So I'm guessing that will have something to do with it.

One more thing. This past week I changed the steering, throttle and shift cables and also did a full tune up of plugs, wires, cap and rotor. And, my son wired in a new stereo wiring harness. We didn't touch the MDC at all.

The boat also sits in the Missouri sun under a cover during the summer. I'm sure it gets well over 100 degrees in there during the day. I know this isn't ideal, but for now it's the only place we can store it and have it accessible (and still afford to keep our home).

The attached picture is not from my boat, it's one I found on the internet to give you an example of what mine looks like. Mine looks just like that, but it's raining today and I don't want to get under the cover to take a picture of the gauges.

I know this is a long post but hopefully all the information can help with suggestions. Do I just need to replace the MDC with what Ron has available? Is it possible that the MDC computer is still OK, and it's some other problem? Or have I just been lucky that it has worked this long? I'd like to keep the current system going if that is at all possible. Any help and suggestions would be appreciated.