I have a 2004 Carver with Volvo D12 diesels. The analog gauges are very inaccurate. I have new Garmin GPSmap 7612's and would like to know if the engine can be made to communicate with the Garmin units? Thanks, Doug
Possibly. See your 7612 manuals; "Owners" and "Installation" manuals respectively probably say something like this: "The gauges and graphs provide various information about the engine and environment. To view the information, a compatible transducer or sensor must be connected to the network." "You must use a Garmin GPSMAP J1939 accessory cable when connecting the chartplotter to the J1939 engine network to prevent corrosion due to moisture. Using a different cable voids your warranty." The 7612s are at least one generation older than Garmin's current offerings. Some analog gauges can be adjusted (e.g., tachs), and some inaccuracies can be fixed by replacing senders (e.g., fuel). Or you might be able to replace existing analog gauges with digital gauges (e.g., Aetna or CruzPro) often using existing senders. -Chris
My 2004 Carver with Volvo D12 diesels shows 530 rpm at idle and 2200 wot- any chance this is accurate?
Unless you really know better, I'd go with it.. A hand held tach would be the better to compare with. There have been a few Volvo to Garmin questions on YF. Please do some searches and find past notes.
How can you tell they are? And are you sure they are analogue? The D12 are electronically controlled (EVC, in Volvo jargon), and their instruments are actually digitally driven, also if shaped like the classic round gauge with needle. In fact, there should be a small LCD display inside the tachometer face, than can show several data in digital format. If that's what you've got, connecting the CAN bus (i.e. the cable carrying all the instruments data) to the chartplotter should be feasible, but you're unlikely to get any different reading. Those engines are rated for 2300 rpm, and that's what you should reach at WOT. Doesn't mean there's anything wrong with the tachos, though. There's plenty of boats around that for one reason or another can't reach the rated WOT (not that it's OK, mind - you'd better fix that). Anyway, the best/easiest/more accurate way to check the exact rpm is to go down the e/r with a laser hand held tacho, as CR suggested. Of course it can't replace the dashboard tacho, 'cause you can only use it inside the e/r, but since you can buy one online for 20 bucks, it's well worth having even if you'll only use it for occasional cross-checks.
