how to repair gauges

[Kick01]

I have a 2000 Malibu Sportster and bought it new in 2000. I keep it on a boat lift for the summer on a lake in Michigan. I went to use it yesterday ( have not used it in about 3 weeks) and for some reason none of the gauges work?? no TAch, no oil, no temp etc. I thought it was a fuse so replace both of them but it did not help? Any suggestions on how to fix???

[Zac]

Hey mate - try posting this in the maintenance tech info troubleshooting section and I think you'll get some great suggestions. Wish I could help but not my area of expertise!

[dlb]

Sounds like a main power issue. Check the ground and power wires first since all gauges are dead. Use a multi meter if available.

[MalibuNation]

Moved this for you ... where are you in MI? ​

[Pistol Pete]

In that era the Medallion control units were known to fail (aka MDC).

If you take the pitot tubes off and any water comes out, there's your problem.

Otherwise, here is a fault trace guide.

Here is a good thread on a repair.

[Bturner]

You didn't say if the boat actually started. If not check to make sure the safety lanyard is connected. If so jump the switch to make sure it hasn't gone bad. You'll get no gauges and no start with a disconnected or bad switch.

If it did start you're probably on your way to trouble shooting the MDC. As others have stated the early MDCs were known for issues. Water intrusion, grounding and bad power in general can all cause your issue along with just a blown MDC of course.