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Hark

Replaced the Medallion box, but gauges still don't work. What now?

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Hark

I would appreciate any help you can provide. I recently bought a used 2000 Sunsetter LXI, and the gauges didn't work. After doing some research, I purchased a replacement gauge module from Bakes. Now the oil pressure and fuel gauge work, but none of the other gauges work. Would love to get everything working before I put it away.

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Bozboat

when you say "replacement gauge module" are you referring to the round multi gauge or the medallion dash computer?  You mention the fuel gauge is working and the oil pressure, so you are missing the volts and the engine temp?

Congratulations on your LXI, they are really fun boats and are easy to work on, lots of good information here on this forum.    

 

Edited by Bozboat

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Hark
13 hours ago, Bozboat said:

when you say "replacement gauge module" are you referring to the round multi gauge or the medallion dash computer?  You mention the fuel gauge is working and the oil pressure, so you are missing the volts and the engine temp?

Congratulations on your LXI, they are really fun boats and are easy to work on, lots of good information here on this forum.    

 

Sorry, the Medallion dash computer. I am missing, speedo, RPM, voltage and engine temp.

Thanks! I have absolutely LOVED the boat so far. It has plenty of seating for cruising with family and friends, tons of power, and a great wake for skiing.

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drh

Do all the gauges buzz and reset at key on? Did this change before and after replacing the MDC?

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Hark
6 hours ago, drh said:

Do all the gauges buzz and reset at key on? Did this change before and after replacing the MDC?

The fuel and pressure buzz after the MDC, but nothing else. Before the MDC nothing worked.

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Eagleboy99

It could be that the gauges themselves are pooched.  The stepper motors die.  The sad thing is that there are reports of guys buying new Medallion computers (POS if there ever was IMHO) that get immediately fried buy the defective gauges.  Hope that is not you.  Assuming that it is the gauges, you are in for spending a LOT of money on replacement gauges.  Bakes has some but they are insanely priced.  Greatlakesskipper, too.  Mine are going to be replaced by lovely analog Faria gauges this winter.  I am tired of years of craptastic  performance from the factory  system.

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Hark
On 8/24/2018 at 5:59 PM, Eagleboy99 said:

It could be that the gauges themselves are pooched.  The stepper motors die.  The sad thing is that there are reports of guys buying new Medallion computers (POS if there ever was IMHO) that get immediately fried buy the defective gauges.  Hope that is not you.  Assuming that it is the gauges, you are in for spending a LOT of money on replacement gauges.  Bakes has some but they are insanely priced.  Greatlakesskipper, too.  Mine are going to be replaced by lovely analog Faria gauges this winter.  I am tired of years of craptastic  performance from the factory  system.

Is there a way to test the gauges?

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Eagleboy99

All the KM gauges will buzz and sweep the face if they are working correctly.  Interestingly our new Nissan gauges work this way as well.  IOW, when you turn on the ignition, there should be a short buzz then the gauges  will go 0 to  the limit and return.  Same thing happens when you turn them off except they go to limit then zero.  You could try swapping the connectors  from one gauge to another since the bus carries the signal and the wires are not gauge-specific.  No buzz, no love.  :)

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Eagleboy99

For the record, my RPMS start at 3500; water temp is ALWAYS 165F; oil is 10-70; and  fuel is a mystery.  Right now only my KM speedo works.  Quite accurately I must say.

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Cazan
On 8/24/2018 at 5:59 PM, Eagleboy99 said:

It could be that the gauges themselves are pooched.  The stepper motors die.  The sad thing is that there are reports of guys buying new Medallion computers (POS if there ever was IMHO) that get immediately fried buy the defective gauges.  Hope that is not you.  Assuming that it is the gauges, you are in for spending a LOT of money on replacement gauges.  Bakes has some but they are insanely priced.  Greatlakesskipper, too.  Mine are going to be replaced by lovely analog Faria gauges this winter.  I am tired of years of craptastic  performance from the factory  system.

Take some pics and do a write when you do this.  I think a lot of people will be interested in this. 

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drh

Here's the Medallion troubleshooting guide if you want to go through it.

I would try to switch the connectors from a known working gauge to a bad gauge as suggested just to be sure that's not the issue but many times if the gauges don't move at all at key on they are indeed the problem. If switching the connectors doesn't work then start measuring resistance values between pins on the 18 pin connector as directed by the troubleshooting guide.

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Hark

Thanks for all the help everybody! I will let you know what I find out.

 

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cowwboy

Also may try plugging on gauge at a time in. I had a tachometer that would cause an issue and make all of the gauges quit working or work intermittently. 

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bushwhacker

Inferior product, seems like too common problem, way too many failures. Need class action

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Eagleboy99

Yeah, maybe.  But computers and water do not mix.  Plus the KM system was designed with one incredible flaw:  the pitot tubes going directly into the box.  Had there been an outside sensor, it would have cut failures substantially.  That all said, the gauges are still crap - Airguide speedos for instance from the 70's are STILL running.

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bushwhacker

I understand but the pitot system uses air pressure right? It being a closed system some water enters the lines but doesn’t replace the air in a closed system. Unless there is a diaphragm failure at the computer box. I have a working system but had to replace the Speedo and tach.  Installed a Faria GPS Speedo 4” prior to buying used gauges still using the GPS Speedo.

Edited by bushwhacker
Added

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notaloser

I ran into the same issue on a new-to-me boat that had water damage. I replaced the MMDC with an equivalent new-old stock computer only to find that 3 of the 4 stepper motors in my cluster did not work at all (i.e. no buzz or needle movement). I couldn't justify the cost of a brand new cluster, so I took my chances replacing the steppers on the gauge PCB.

Getting into the gauge was very tedious, then removing solder from the connector and stepper motor pins was hard, as well, even with the right tools. I ended up damaging some of the circuit and had to repair with copper tape. All 4 gauges are working now, but I won't claim high confidence in the repair lasting very long.

It can be done - but you need to be INCREDIBLY patient. Don't dump too much heat into the board or the circuits WILL lift. The stepper motors are standard GM parts and cost a few bucks for a set on Amazon, search "x27 168 stepper"

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justgary

Thanks for that info.  I have one dead gauge on my bench (I put a perfect pass display in its place) that I can practice on. 

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notaloser

Have a few sizes of solder wick and a good soldering iron handy or removing pins from the board is risky

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Eagleboy99

If you have the 4" gauges (sadly, mine are the 5") it can be a super easy swapout and bypass of the MDC.

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Hark

OK, so I FINALLY got to troubleshoot using the MDC troubleshooting guide. There was no voltage between pins J and K of the 5 pin MDC connector, but there was 7VDC between pins 2 and 3 of the MDC. According to the troubleshooting guide, that indicates a bad wiring harness. Anyone have an idea what I am up against trying to replace that, and where I might be able to get one?

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drh

So on the gauges that don't work you don't get voltage at the 5 pin connector but on the working gauges you do?

If so, then when you switch connectors between a working gauge and non working gauge the problem should follow the connector. I would try plugging a good connector from a working gauge to all the non-working ones to confirm that all your gauges are operational before investing more time and money. Once you know that your gauges aren't the problem you can start working on the wiring. Otherwise it may not be worth trying to salvage the system.

Once you've confirmed that your gauges are ok I would start by checking the splices where 5 pin wiring harness at the output of the MDC is spliced into the multiple wiring runs going to all the gauges. I have never had to dig into this so I don't know how hard it is to get to but you may get lucky and see an obvious loose connection or corrosion at this point. If access is easy enough it may be worth it to redo all the splices on any connector you don't get voltage at.

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Hark

Thanks for the help. Hoping to get back to it tonight, but tomorrow night at the latest. Will post updates.

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Hark

I checked the voltages at the back of the gauges last night, and I am getting roughly 7 volts at all the gauges.

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