View Full Version : 2006 Prostar 209 ground wire

05-25-2012, 10:24 PM
I've been having issues with my gauges and bow light and I think it may be attributed to a bad ground. The gauges work sometimes and all of the sudden they go dead. The bow light seldom works. I have cleaned all connections on the battery terminals. I also found the ground bar under the dash and inspected and cleaned those grounds as well. I would like to find where the main ground on the engine block is located but I can't find it. I have the MCX in this boat. Anyone have any ideas. Any other suggestions as to what might be the problem? Thanks

05-30-2012, 10:20 AM
I had a similar issue on my 209 last year where the boat ran fine but had no gauges or they would intermittently work. I unplugged every connector under dash and cleaned all the connections especially the connector to the medallion unit. My understanding is that MCs use digital gauges which are controlled by a computer (brain box) using a digital protocol like CANBUS which is based on the fact that every gauge has the same connector and wire colors running to it and all connections routed back to the "brain box".

Pull the main connector, which requires removing a small screw in the center of the connector and clean with starting fluid. Do not use contact cleaner or dielectric grease, these can be slightly conductive. I have learned from agriculture technicians that these digital protocols are very sensitive and any voltage leaks can cause issues which is why they recommend starting fluid. I also pulled the two black airlines from the pitot tubes (speedo pickups) and blew them out. When I removed mine a bit of water drained out. I’m not certain which was the cause of the gauge problem but, given the lack of maintenance and care the P.O. gave my boat, everything is coming back to corrosion in the wiring connectors.

Also, if you had a bad engine ground the engine should not run.