View Full Version : Gages losing power?

02-27-2008, 10:56 AM
Has anyone ever had their gages stop working? It's never happened before until last weekend. They started losing power about 5 minutes after the engine was running, and went on and off a couple times before completely going out. I'm guessing it's a bad ground or a broken connection in the power wire somewhere.

Any suggestions?

02-27-2008, 11:15 AM
I have a common problem on my '02 of certain gauges occasionally going dead. Not sure if it applies in your case but I've been told that running a separate ground from the affected gauges is the fix.

02-27-2008, 12:04 PM
From the looks it looks like you have the same boat. 2000ish X-Star.

The gauges cutting outt are somewhat of a normal propblem. .... every once in a while my oil or my fuel gauge won't read, but long behold turn off the boat to switch riders and viola it works again. If I recall it has to do with the ECM....the little black box under the dash.

Not sure if you lost all your gauges or just a couple. If you lost all could be a bad ECM which is/was a common problem. If you just lost a couple most likely the "other common problem that most choose to ignore. They should kick back on when you restart the boat.

02-27-2008, 01:06 PM
I had this problem with my boat, 2003 X7. All my gagues went dead, I read about the ECM ets, my problem was at the battery itself. The wing nuts on the top of the battery that holds a seperate positive and negetive cable were lose. After I tightened them the problem was solved. My gages also flickered, probably due to the bad connection.

02-27-2008, 03:48 PM
hmmmmm....i hope it's not the ECM

i was up under the dash looking around and found a semi-loose connection on a ground block. it was connected, but the screw was loose. i need to just turn on the boat now and see.

i also have a couple screw tips coming up through the dash that i want to cover, no telling what they could poke through and what kinds of short circuits that could cause.

02-27-2008, 08:20 PM
Its the MDC, which is the black box up under the dash; the ground to the MDC or the gauges themselves. There have been a few threads discussing the issue that should be searchable.

02-27-2008, 08:26 PM
I had this problem with my 07' x-2, it ending up being a loose ground on the battery terminal. I put some lock tite on the battery terminals and tightend the wing nuts and i haven't had the problem since....

03-10-2008, 09:35 AM
Update on the gages......

So this past weekend my Dad and I investigated a little further and determined the gages are getting power...the lights come on but they just don't read anything. Located the MDC and tried to monkey with it and the connections in case something had come loose. At one point, the hour meter was showing up but then it vanished once again.

So the question is, where do I buy this MDC? I'm sure the dealer can find me one, but if I don't like their price...where do I look?

03-10-2008, 10:08 AM
Ordered one for my 02 last Monday from BAWS and was skiing on Sat. Best price I could find and great service to the middle of nowhere.

03-10-2008, 10:37 AM
Before you replace anything, remove the battery cables and do a few things- clean the cable clamps and terminals, disconnect the plug from the MDC box and make sure there isn't any corrosion on the terminals. If they are corroded, Tarn-Ex can remove it, then coat with dielectric grease. Then, measure the resistance from the battery negative to the MDC plug negative. You want to see no resistance but .1-.2 ohms will work. If it's a '99 or 2000 model, adding a heavier ground was recommended to fix this issue. Reattach the MDC plug and tighten the small bolt, but don't crank it too tight. Reattach the cable clamps and when the negative goes on (last), make it go on in one move, without tapping it repeatedly. These voltage spikes are one cause of this kind of failure.

03-10-2008, 05:37 PM
i'll see if i can't do all this tonight or tomorrow

03-10-2008, 06:06 PM
I had this problem last year on my '99 sportstar. Turned out to be the MDC, it was full of water. Got one from MC of Charlotte, I think it's a common problem.

03-10-2008, 10:09 PM
I hadn't seen what your your boat is but now that I know- I assume you have a pair of rubber lines plugged into the MDC, from the speedos, right? If they have never been removed and purged, you can definitely have water get into the MDC.

03-11-2008, 12:39 PM
hmmm....is it bad that i think i heard water sloshing around in it?


03-11-2008, 12:52 PM
Ya think? I don't know if yours can be opened but disconnect the plug from it ASAP and remove it form the boat. If you can open it, do that and wipe any water off of it and use a hair dryer to make sure it's good and dry. If it looks like the solder joints and traces are corroded with gray or white crusty stuff on the parts and board, you'll probably be better off to stick a fork in it and get a new one. If you get it dry, it may work, but it won't be permanent.

The only reason it's a common problem is due to not blowing out the speedo lines when winterizing, or occasionally during the season.

03-11-2008, 05:16 PM
hahaha.....well, i'll see what i can do with it.

i've had great luck getting cell phones to work after they go for swims...cross my fingers

03-11-2008, 07:30 PM
Yeah, I dumped my cell phone in water quite a few times and in one conversation with AT&T customer service regarding my dropped calls, someone mentioned the fact that the RAZR has a little round white sticker that turns colors when it gets wet. Still white and they said it turns red when wet. I did remove the battery immediately, though, and that's one thing you haven't been able to do. This can result in pins on devices corroding due to electrolysis, and generally can't be repaired.

Who knows? You might get lucky with it.

03-12-2008, 12:30 AM
Don't shake your heads at me...I've only had the boat for a year, I couldn't possibly be the one to blame for this mess:


Ok, so I cleaned the circuit board very thoroughly and put it in the oven for maybe 30 minutes to dry it out....on low low heat (around 100 degrees). It's sitting under a little fan now just for added drying.

I'll hook it back up tomorrow and see if it works.

My question is: How do I prevent water from getting in here again? How exactly did it get in to begin with?

03-12-2008, 03:37 AM
If you look at the place where the speedo line(s) connect, there's a little diaphragm inside that probably leaked, for one reason or another. Usually, it's due to water going all the way to the MDC box. At the transon, there's a brass tube (called the ballast), mounted vertically, with one line at the bottom coming from the pitot in the water and the top line going to the MDC. The diaphragm is supposed to be pressurized by the air above the ballast tube, not water. Air can be compressed when pressurized,water can't. (No, I don't want to get into the discussion about how water can be compressed down to eight places to the right of the decimal). Hydraulic pressure from the pitot makes these fail, pneumatic pressure from the pitot doesn't. If it works at all, I wouldn't suggest connecting the line to it again. It already leaked and water will just get in again.

Low pressure compressed air is how the lines should be purged, from the front end. The water that came out looks like it has silt and algae in it. It could be a situation where this silt went into the ballast and when it settled, it acted like a check valve, letting water pressure go up the line, but it couldn't let the water out. Sustained pressure probably made the diaphragm fail and the water then crept forward. It could also be a situation where water got into the space where the diaphragm is and froze. When it expanded, it caused the failure. Either way, that part of the MDC is done working and you'll need to use another way to measure your speed.

03-12-2008, 08:50 AM
So the little box that has the diaphragm (where the speedo pickups plug into) can I pop that off? I could tell that it is a separate piece, but I didn't want to go breaking stuff off.

Ok, so I need to take the tube off the connection at the transom and blow it with air from the front? Is this correct?

I noticed one connection on the circuit board that had a broken connection, my roomate is good with electronics and such, so maybe with his help I can repair that and then plug it all back up just to see if it powers the gages.

03-12-2008, 09:45 AM
If the pitot is clear, you shouldn't need to remove the tube at the rear. If it doesn't blow out without removing it, it'll need to be cleared.

I don't know if the diaphragm can be removed- maybe one of the dealers here can help you on that.

If you or your roommate can solder, have a pencil tipped iron and the lead isn't too short, it may be repairable. If tee lead is too short, you'll be better odd replacing the component. Wet components usually fail. I don't think I would spend too much time repairing it- if the right (or wrong) components fail, it can take out the gauges themselves.

03-13-2008, 09:58 AM
Well, I popped off that diaphragm from the MDC just to see what was behind it. I guess those are some kind of pressurized transistors or something, they're round, watch-battery looking components with a tiny pin hole in the back that faces out. They are connected through the board with 5 pins each. When everything is right, I guess that diaphragm is air tight and those transistors can pick up the change in air pressure.

So my question is this, since I have perfect pass, I don't really need the extra speedo....even though it's nice to have. All I'm really concerned with is my other gages working.

I guess I'll check to see what a new MDC runs, and then I need to check the lines and the speedo pickups.

03-24-2008, 10:18 AM
To update everyone, I ordered a new MDC from my local dealer and installed it Friday night. All the gages work like a charm now!!!!

Thanks for everyones help!!!!!!!!!!!!

03-24-2008, 10:29 AM
Go to the transom and look for the speedo ballast(s), to make sure they haven't burst. If it/they have, you can use a torch and the same kind of solder that is used for plumbing, or take it to a radiator shop.

03-24-2008, 04:20 PM
ok, i will check on that.

i did purge the water out of the speedo lines too, i forgot to mention that.

04-13-2008, 02:50 PM
I just got back from Tainter lake (yep, there's still ice out there) for a test run before I loaded up the ski equipment to take my first run. This is my first time with my new 2000 MC Prostar 190.

Anyways, the boat ran like a dream (I upgraded from a 1976 Nautique) except my gauges quit working after a couple passes in the open water. They were working fine and at some point I noticed the right speedo not working, then the left speedo wasn't working either. As of right now, the oil, water and speedometers are froze. My hour meter isn't working either. All other accessories are working fine.

Any thoughts?

04-13-2008, 03:44 PM
I checked the battery terminals and those checked out ok. I looked under the dash again to see if I could spot any loose connections and noticed water running down some of the wiring. I wiped the hoses lightly and somewhat tracked them back to what I think is the controller. I couldn't see much because of the heater hose but without barely touching the connections, the connector fell off. For whatever reason, it will not go back on.

Since the boat is still under warranty, I'll probably run it back to the dealer. However, do you think this is the problem with all of my gauges not working?

Engine Nut
04-14-2008, 08:17 PM
I just got back from Tainter lake (yep, there's still ice out there) for a test run before I loaded up the ski equipment to take my first run. This is my first time with my new 2000 MC Prostar 190.

Anyways, the boat ran like a dream (I upgraded from a 1976 Nautique) except my gauges quit working after a couple passes in the open water. They were working fine and at some point I noticed the right speedo not working, then the left speedo wasn't working either. As of right now, the oil, water and speedometers are froze. My hour meter isn't working either. All other accessories are working fine.

Any thoughts?

Is that Tainter Lake by Menomonee Wisconsin? I graduated from college there many years ago and still have many fond memories of Tainter Lake and the Menomonee area.

04-14-2008, 10:27 PM
Yep, it's in Menomonie. Great place to live....

By the way, I ran the boat over to the dealer and they found that MCR (??) board full of water. They're trying to get it back running for me by Weds. I'm not sure what they cost.

04-14-2008, 10:46 PM
Second thread about this in a month. People and dealers not purging the lines when the boat is winterized is usually the cause. The other cause is that the diaphragm leaks up front and water bypasses it, getting into the MDC box. Not sure why they don't just put a sender at the transom, but they didn't ask me, did they?:rant: :D

05-04-2008, 09:10 PM
i need one of these mcd for my boat...anyone know where you can get the best prices on them