Hello, I am working on my friends boat it is a 2001 Maxum 21ft with a Mercruiser MCM 5.0 EFI it starts fine and every so often when cruising will have the warning horn continuously sound and at the same time the gauges all drop to nothing. The boat does not miss a lick and continues to cruise fine when this happens. If you continue to cruise the horn will stop and the gauges will all come back at the same time. (The speedo never works). I pull the engine codes and it always has a code 12 which is the normal code. The gauges have a single connector that is connected to the harness with a bunch of butt crimps which I will probably solder. I am thinking the gauges are losing either power or ground. Anybody have any ideas?
I agree with your assessment either 12V supply or return has an intermittent connection. Since the engine continues to run the fault is at the helm wiring after the ignition switch.
Thank you for the reply. Very good information. I am going to work on it this weekend but wont be able to test until next weekend. I will reply with results. I am going to redo those butt splices and check the ign switch connections and if that does not fix it I am going to figure out which are the power and ground and then put a meter on them and duplicate the problem and see what I got or don't have when it occurs. Then isolate to ground or hot if one is not there. I may need a wiring diagram. Thanks again!
2001 Maxum 21ft horn sounds gauges quit working
Linear Mode
