2000 SSLXI Speedometer/Tachometer troubleshooting

[dlx742]

Hi, I have a new to me 2000 SSLXI that my fiance's family has owned since new. When it went into the water this year the speedometer and tachometer were not working, however the hour meter and all other gauges worked fine. After a quick search here I solved the speedometer issue by unclogging the pitot tubes with a paper clip (props to the guy who convinced me to now keep one in the glove box). I am still trying to diagnose the tach.

This morning while skiing I noticed the speedometer was not working and the needle was sitting on the lower limit. I tried clearing the pitots again with no luck, so we finished the session guessing how fast we were pulling.

Later today after another search I ended up doing the following:

- cleared the pitot lines with compressed air

- checked the MDC for water in the pressure sensor - was dry

- checked ground on engine and at distribution block

- followed the MDC trouble shooting guide

- disconnected all gauges and reconnected one at a time, speedometer resets but tachometer does not reset. oil/cool/volt/fuel gauge still works along with hour meter

- connected different plugs to each gauge with same results

- read 7 volts between J and K at all points on harness

- swapped pitot lines at MDC between primary and secondary

Since my other gauges work and the harness has voltage I am starting to think the gauges themselves are defective. I need a speedometer for pulling people so I think getting a replacement will be my next try. I'm sad the tach isn't working but its second in priority to the speedo.

Is there a way to test the gauges themselves?

What are some replacement options? (new/used/alternatives)

Could it be something other than bad gauges?

For the next few days I guess I will try using my phone for a speedo.

Edited August 5, 2015 by dlx742

[Jimmy Buffett]

Bakes Marine may have replacement gauges. It could also be the MDC has gone bad.

[John I.]

How about using this as an opportunity to install Perfect Pass?

[Bozboat]

I ditched my pitot tube system and replaced it with this GPS upgrade.

http://www.nauticlaugic.com/nl3.html

Unfortunately I waited until after the MDC got soaked with water coming up the pitot tubes hoses into the dash computer.

[dlx742]

Bakes Marine may have replacement gauges. It could also be the MDC has gone bad.

I found the gauge on bakes marine, but the 2-3 weeks lead time hurts

How about using this as an opportunity to install Perfect Pass?

I gave it a thought, but I don't know too much about it.

This morning I ended up mounting my phone to the dash and used a speed app. Tomorrow I am going to try mounting an old Garmin GPS to the windshield.

If anyone has a working speedo they would like to sell please let me know.

[dlx742]

I ditched my pitot tube system and replaced it with this GPS upgrade.

http://www.nauticlaugic.com/nl3.html

Unfortunately I waited until after the MDC got soaked with water coming up the pitot tubes hoses into the dash computer.

That looks really cool. Is there any lag?