View Full Version : Three Gages Died today...

Skier Steve
06-14-2014, 09:26 PM
I have a 2002 Mastercraft 197. Ran well the last two weekends. Today, lost THREE gages: The tach, the left speedo, and the engine temp. (I have an aftermarket Perfect Pass in the right speedo hole).

I find it odd that THREE gages died all at the same instant. From reading, suspect that the MMDC may have gone bad.


The label says 7018-00001-01. I've seen replacements on the web for $500 +, and don't want to spend that kind of money if the MMDC is NOT bad.

Read on one site that if ONE gage is bad, it will mess up the others. Not sure if that's true.
On my boat, the fuel gage and volt meter still work OK. But the other three gages are dead.

The needles DO "quiver" on start up, but that's it. They don't swing way up and then fall back. They just quiver.

Any help would be appreciated!

Thanks in advance....

Jeff d
06-14-2014, 09:31 PM
Could be an mdc failure. Could be a single gauge on the bus making "noise" and causing the 3 gauges down the line to stop working. It's not likely senders.

Here's the troubleshooting guide:

I worked through it numerous times and got inconsistent/inconclusive results.

Apparently you can also send off the mdc to medallion for testing and they can tell you if it's bad or good with certainty.

06-15-2014, 07:29 AM
The gauges are set up to communicate on a bus typology (a string of pearls if you will) in which data is sent to all the devices but only data addressed to a specific device is displayed by that device. Horrible design that is pretty much a copy of very early Ethernet origin. This leads to any errors occurring on one device to effect all the devices on the bus. Hardly a robust architecture to choose.

The early implementations were know for their issues and getting them to run for more than a season or two can be challenging. I've seen a recent post where the owner has replaced all of his gauges with conventional gauges for a fraction of what a new MDC or OEM replacements would cost. If I were having issues I'd be hard pressed to spend big money on an MDC or another set of Medallion gauges that will most likely fail again in a couple years.

If you want to stay digital you may want to consider looking at Livorsi. They make a similar digital product that should be able to be retro fitted. I had also considered this for my 03 X2 that had multiple gauge issues but sold the boat before getting to that point.

Skier Steve
06-15-2014, 07:51 AM
I'll try cleaning the contacts first. Took a quick look at them before I left the boat and they LOOKED OK, but I'll come back with some contact cleaner.

Sorry to hear that the MDS test protocol may be inconclusive. Was hoping to find a way to be SURE before spending big bucks.

Anybody know of a LESS EXPENSIVE source for a replacement MDC, if that's the problem?

Does anybody sell "re-conditioned" units or something like that?


Jeff d
06-15-2014, 09:44 AM
The troubleshooting tests could be conclusive in your case. The were just not in my case and anecdotally many others. I'm the one bturner2 referred to who removed my MDC and went with standard analog gauges. It's definitely the way to go IMHO if you need to replace anything more than a single gauge or two:

I'm not aware of anyone selling refurb MDCs and I'd be hesitant to pay anything for a used one given their track record. Bake's marine sells them new for $290 if I recall correctly which was the best price I found anywhere. My whole 6 gauge set was $172 so I went that route.

Skier Steve
06-15-2014, 08:14 PM
I'm a little afraid of swapping out ALL of the gages. Think I'd rather replace the MDC (if that's what is wrong). Only saw the mini at Bakes, but maybe they also have the "big one".

I read another post that talked about two in-line fuses in the wires to the MDC. I'll have to look for them on my boat next week. I'm kind of surprised that Mastercraft would put IN LINE fuses on something like this!? You'd think they would use something on the breaker panel ??

I'd like to have some REPLACEMENT fuses on hand in case they are bad. Anybody know what kind / size they are?


Jeff d
06-15-2014, 09:07 PM
Mine did not have inline fuses. If you had a fuse issue all gauges except perfect pass and the depth sounder would have stopped working. There are no fuses for individual medallion gauges.

I didn't really pay attention to exactly what Bake's had available but just casually noticed at one point that they seemed to have a better price that I had found elsewhere when I looked at replacing my MDC. You may be right and they may not have the right one.

By pulling apart the dash for troubleshooting you're going to do 90% of the work that it would have taken just to replace the gauges and eliminate the MDC. I should know as I pulled everything apart 4-5 times, cleaned connections, reseated connectors, cleaned grounds, followed the troubleshooting guide with a multimeter, etc. over the course of 3 seasons. Each time I got different results and came to different conclusions. I wish I had just replaced it all from the beginning and I would have saved at least 5-6 hrs of time.

If you can't confirm with 100% certainty that the MDC is bad and also that the gauges are good (or vice versa) I'd be way more "afraid" of swapping the mdc out and those gauges still not working. It would be strange but this system sucks so bad a triple gauge failure wouldn't really surprise me that much. Something could have "zapped" all three at once. Then you'd have spent $290+ and still have to go out and try to find matches for the affected gauges. You might be stuck waiting for used gauges to pop up on eBay and then they wouldn't necessarily be "known good". You could end up at $400+ pretty quickly and still have a gauge system that's flawed by design and difficult to troubleshoot the next time something goes wrong.

I would do one of the following:
1) leave the dash together and send the MDC to medallion for testing. This requires minimal work on your part and should give you certainty on whether the MDC is bad or not. I'd guess there's a fee for this but it shouldn't take more than 30 mins of work on your part to remove the old one, pack it up and send it off. If it's bad then replace it and hopefully you're done. If it's good either troubleshoot further on your own or switch to option 2 (and sell your now "known good" per medallion MDC)

2) Buy an analog set of gauges that you like and swap them in.

06-15-2014, 11:52 PM
You could call Medallion. I think it is the cheapest way to replace it. I ordered a new MMDC from them. At the time, a couple of summers ago, they had a service to repair your old one as well. I agree with the alternate gauge route. If this freaking thing fails again I will be switching over as well, thanks to Jeff D's write-up.

06-16-2014, 08:18 AM
Pulling everything apart and cleaning got me nowhere. I was also told at the time (this was like 6 years ago) that it could be a bad ground and went down that rat hole too. I basically started at the engine ground and checked/cleaned everything from there to the dash. Pulled everything apart and inspected, cleaned and tightened every connection along the way with no joy.

Later that spring I added PP and had problems getting it to work. PP was very aware of the issues with the Medallion gauges and sent me a noise filter to use with the Medallion gauge solution to fix my PP issue. Unfortunately the Medallion gauge package during those early years were not very reliable (as were the brake components of that name used during the same manufacturing time frame). Not sure how much money or time I'd be willing to invest in that package but this is something only you can decide. The only down side I see on replacing the gauge package is losing the MC logos on the gauges. However having gauges that actually work is much more important than the logos IMO.

06-20-2014, 05:58 PM
Skier Steve, I need a new MDC box (6607-20009-01) too. I was surprised to find that my location MC dealer wanted $500+. I called Medallion today and was able to get a new one from $273 + $15 shipping. I was told it would take 7-14 days for me to receive it as they may have to build a new one from scratch if they are out of current inventory. Tracy at Medallion is the person to contact. She can be reached at 616-850-8091. Hope this helps save TT folks some money. Mastercraft is marking up these up nearly 100%, I’m in the wrong business

Skier Steve
06-22-2014, 11:58 AM
Thanks Tssayre!

I went through all the diagnostics on Saturday, and concluded that it MUST BE the black box. I'll give Medallion another call on Monday and try to order one from Tracy. Thanks for the tip!

Skier Steve
06-23-2014, 10:18 AM
Ran through the diagnostics this weekend. Checked the ground and the ignition switch and the kill switch. Tried pulling off ALL of the gages and then plugging them one at a time. NOTHING got the three bad ones to work.

Checked the INPUT to the MMDC. Found we had 12 volts coming in as expected, and 4 volts on the "data wire" from the engine (trouble shooting manual said 3-5 volts).

At this point, I've got to believe that the MMDC is bad. INPUTS are OK, but no outputs.

So, I've followed tssayre's advice and ordered a new one from Medallion. MC wanted ~ $800, and Medallion sold me one for only $350. Still pricey, but better than $800!

Thanks to all for their input --I appreciate it.

Let's hope that a new "black box" really IS the fix we need....

06-23-2014, 11:02 AM
I had a similar issue last season. After getting caught in a rainstorm, my tach (which also houses the LCD for temp, hours, etc) had picked up some moisture/condensation. At the same time, all my gauges failed but I didn't immediately figure out the tach was the culprit. On a hunch, I unplugged JUST the tach and all the other gauges started working again fine. . . plugged it back in and they stopped working. In my case, I got lucky--a couple of days in sunlight evaporated the moisture out of the tach and all has been trouble free ever since.

Skier Steve
06-23-2014, 11:10 AM
I was REALLY hoping that unplugging some of the gages would fix the problem, but no joy.

I unplugged the ALL and then plugged them back in one at a time, hoping that something would come back on line. But, the only ones that worked were the fuel gage and oil pressure -- with or without everything else being plugged in.

I had THOUGHT that the volt meter was working, but upon unplugging it, found that it just DID NOT MOVE. The needle just stays at ~ 13 volts.

Glad that drying out the tach solved YOUR problem....

06-23-2014, 12:28 PM
Skier Steve, I need a new MDC box (6607-20009-01) too. I was surprised to find that my location MC dealer wanted $500+. I called Medallion today and was able to get a new one from $273 + $15 shipping. I was told it would take 7-14 days for me to receive it as they may have to build a new one from scratch if they are out of current inventory. Tracy at Medallion is the person to contact. She can be reached at 616-850-8091. Hope this helps save TT folks some money. Mastercraft is marking up these up nearly 100%, I’m in the wrong business

Some interesting statements made by Medallion. There must be some demand that they wouldn't be able to keep them in stock. The price their selling them for is probably real close to break even and most likely a PR move since the product was poorly designed and so many people are having to drop big money to fix their mess. I mean really think about it. How many people had to spend anywhere near $300 to fix their gauges prior to the junk they started selling the boating industry? I think I may have replaced one tach in all my years of boating. I would be more nervous if I were running one of the newer LCD displays that all the boat manufactures are putting in these new boats. I wonder how much those will be going for 10 years down the line.

Skier Steve
07-07-2014, 09:46 AM
Thanks for all the help, guys!

Turns out it WAS the black box (MMDC).

I called Medallion and got their trouble shooting guide. Found out that the inputs were OK, but the outputs were not. Checked the fuses -- OK. Tried plugging and unplugging gauges - no help. It's GOTTA be the box!

Called Medallion back and ordered one. Cost was $350 -- and they had it to me in less than 1 week (with rush shipping).

Easy installation (4 screws & 2 plugs) and we are back in business!

Much faster (& cheaper!) than dragging it to the dealer (4 hrs away).

Medallion was EXTREMELY helpful! If this one lasts 10 years, I'll be a happy camper!

Thanks again to all for your kind advice. Great to have a knowledge base like this. Saved me a BUNCH of time and $.

Jeff d
07-07-2014, 10:01 AM
Good. Make sure you remove the pitot tube from the mdc as part of your winterization process. The most common way they seem to fail is due to freeze damage. Also, make sure you have it mounted properly with the pitot tube fittings pointed down (there's usually an arrow to indicate proper mounting).

Skier Steve
07-07-2014, 10:42 AM
No problems there -- I've got a paddle wheel!

But you are correct for those that DO have a pitot tube.