research for fix for inaccurate guages, false low voltage, false overheat, etc

[bheninger]

I bought my Epic 22 in March of 1999 from Marine Products in SLC and immediately towed it to my home in Calgary, Alberta, Canada.  I now have 940 hours on my boat and my family has really enjoyed this great boat.  Until I saw your topic I didn't realize I wasn't one only one having this problem.  As soon as I turn on the radio, navigation lights and heater, my gauges go haywire and the buzzer and warning light come on.  As long as I run minimal accessories everything goes smooth.  I'm not that technical and sure could use some help.  Since my boat was one the the first ever made I must have the oldest features going.
Thanks,
Brian

[ATXChris]

What you are describing is just low voltage to the gauges caused by voltage drop in the ground and/or power wires to the gauge computer ( MMDC ).  The majority of the voltage drop on my 99 Epic 21 was in the ground, so I ran an additional ground wire directly to the battery negative terminal to solve the issue.  Before the fix I would have issues of the radio cutting out with too many accessories turned on or radio turned up too loud and low voltage reported in the dash.  Also when I turned on the blower, the temperature would read about 20F higher than with it off.  I figure this is since the temperature sensor is grounded to the engine block and the MMDC ground was experiencing a voltage drop causing the reading at the computer to be inaccurate.

[toyotafreak]

Brian, I'll be in Calgary Modnay through thursday AM...Stampede with my fav customer!!! Where are you at?

[CherokeeEpic22]

Hey guy's when i was on the lake last week my speedometer quit and my accuski faded away is this the type of problems you guy's are talking about also how do you know if it every had a ground wire and hot wire upgrade, i have always had the low voltage at high rpms

[wakejunky]

Ive never had the accuski fade away don't have a factory speedo anymore. are you getting an alarm at high rpms or just low voltage? what does the display say the voltage is?

the power ground upgrade is a 10 gauge or larger wire ran from the battery or perko switch to the DECC and attached at the large lugs. remove the 12v line its making matters worse. the ground it really pointless but its not hurting anything. what is really silly is how we all did this upgrade without even thinking it through. The DECC runs our accessories, blower, horn, lights, shower etc. it has absolutely nothing to do with the gauges or message center. the MDC or MMDC (depending on year) controls and operates the gauges and message center. i even fell for this back in the day. i guess i just wanted an easy fix.

as for the real solution for this? everyone Ive spoken with and or messaged wants to wait for the season to end before trying the repair themselves or sending me their harnesses to repair. if anyone wants to send me their harness now ill be happy to do it. i would post directions but i want to do a couple and check results before we post a how to and have people repairing the harness with bad results or damaging electrical components.

[Echelon73]

I just bought a 1999 Epic 22 about a month ago (I think it was "rsatterfield's" boat).  I bought it from Lake Wylie Marina in South Carolina.  Most of the guages do not work on it.  In fact the only ones that seem to work at all are the engine temp (water temp), and the fuel guage.  One of the speedometers moves a little, but not enough to be accurate.  In fact I'm not sure I trust any of them to be accurate.  I have been reading this thread trying to decide where to start.  Has anyone ever tried just upgrading all the guages to new ones though?  Would new guages work directly off the current sending units on the engine or would you still need some type of controller?

[sailtl]

I had to put all but 2 NEW gauges in my 1999 Epic 21 and it solved all my problems. I would first check to make sure that water did not get into your MDC via the speedo pick ups. I sent my MDC and all my gauges to Medellion over one winter for them to check and inform me what was bad and it was the gauges. I bet if you email Capt Rick he can do the same thing a whole lot faster.

[mysterybike]

Was there ever a definite resolution to these problems?  I recently purchased a 1999 X22.  The two speedos have never worked.  All other gauges have seemed to work but very erratic.  As of this weekend, though, all gauges do not work at all with the exception of the fuel gauge which will work for just a minute or so after startup. After a minute or so, everything is dead in the gauges.  Anyone have any suggestions on how to repair this?  Any help would be greatly appreciated.

Thanks in advance.

[wakejunky]

Mysterybike- this was basically a fix for working but inaccurate gauges when using several high amperage accessories at the same time. Much like what Skibeau posted previously. It is not a fix for broken gauges. It basically makes working gauges more accurate and eliminates issues during high amperage use. Just guessing but sounds like from your description you may want to follow sailtl's lead. You definitely don't have "working" gauges.

[masonlk]

Go with wet n frugal's GPS solution for the speedo. Easy plug in and calibration.

[brad]

Wakejunky:  I'm a slow mover but today I finally moved my MMDC from behind the rear starboard seat to up under the dash as you mentioned last summer.  My accessory buttons started flashing after I got off the lake on Saturday, so I decided to take the first step in addressing the wiring issues.  I too have removed the factory speedo and I don't have the Accuski cruise control connected (installed PerfectPass a number of years ago).  It felt good to remove the excess wiring that is no longer needed.

Sent you an email Doug on the scanning tool and wiring harness.  Hope things are going well with your new venture!

[cyclone]

Old post, I know, but new to me:) My mmdc in my 2001sx is up under the dash, unlike my '00 E22.

What specifically are the shielding mods?? I have the ultimate set of tools, my Dad was a TV repairman;)

[wakejunky]

yup, that's definitely an old post. Walked away from it because there was very little common applications. Each boat seemed to be a one off when I dug into the wires. You basically want to shield the "CAN" wires. Maybe yellow and orange or green, cant remember. The wire info is in the gauge info section somewhere. I replaced the CAN wires using twisted pair theory. you could probably slip some wire mesh over it and ground it. might be easier...... Good luck.

I'll be honest didn't use the boat too much after I did it. seemed to work well

[cyclone]

Thx for the info. Might be sufficient to move CAN bus wire away from power and ground, or to add ferrite beads in the right places. I will experiment...