Did you ever find a solution to this issue? I am having the same exact issue. Even down to the details of taking my boat to my local marine dealer who also talked to a Mercury tech (tech told him the exact same thing in that I would need a "junction box" to make this work. I already have the male to male connector that connects the blue can cable to the merc monitor cable. Please advise if you were ever able to find the solution here. It would be very helpful. Thanks
Send me a picture of what you have at the junction box. Do you have terminator resistors in any open ports ? Often when connecting smart craft items like this or the VesselView mobile (most commonly), there can be confusion around this. Especially on engines of and era early to the smartcraft compatibility years.
To explain, my 2003 mpi mercruiser and others around that age, or before approximately 2005/6ish, came with a purple coloured weather cap in the smartcraft port, when not utilised. This was often mistaken for a terminator resistor cap.
The guy installing the smartcraft device, loom or such like would then use this cap to the open port on any such loom or harness, as per the instructions.
The problem was that the instructions or thought behind that, were of the assumption that the cap that was in the previously unused port, was of the yellow coloured type. The yellow colour indicated that it actually was a functioning resistor. But like I say…most or perhaps even all early engines didn’t come with a yellow cap. Instead they had a simple weather cap of a purple colour. This just won’t allow the device or accessory to function at all.
So…long story short…make sure all open ended ports on the loom and or junction box have a yellow terminator cap in place, or it won’t work. If there is a purple one there (often at the engine end perhaps), in any of the ports…it won’t work.
If the above is all verified and in place…then it can only mean one of a couple of things.
Not sure about that particular gauge you have, but other gauges like the sc1000’s need a master gauge to act as the master to ancillary slave gauges in the array. So for example my sc1000 tachometer is the master to the slave speedometer, fuel and volt gauges.
Is your merc monitor gauge been told it’s the master gauge in the calibration?
Alternatively we go back to the possibility of an open end in the loom somewhere. Any open ended or un utilised port needs to be either in use or capped off and terminated.
Send me some pics and I might be able to help.
