Bolo
Contributing Partner
I've made posts before about my erratically acting tach. But since then it was behaving itself but now, about a week or so ago it quit all together. So, I went on a search for that "one" loose or corroded connection. I checked and cleaned every connect at the tach. I checked and cleaned the harness plug (looks like a trailer plug) below the cockpit. I checked the alternator connection.
My system includes a Balmar voltage regulator (A MC-412, I think) installed by a PO which waits 45 seconds before sending a signal to the tach. This, as the manual says, allows the belts to seat and the engine to "lube up" before allowing it to start charging. So I know about this time lag. I also seemed to remember reading someplace that systems with a "multi-level voyage regulator" may sometimes keep a signal from going to the tach if the batteries are near a 100% charge. So...I turned off the battery charge at the dock for a day, while still running the usual stuff (fans, frig, lights) and started the engine to find the tach still dead.
I did take a reading of the voltage coming from the regulator while the engine was running and I found about .5 volts at idle and up to 1.8 and more when I revved the engine. In short, I tried just about everything I could think of short of actually testing the tach which I don't know how to do. BUt I suspect that the tach may be faulty.
Clint Eastwood once said in a movie, "everyman needs to know his limitations", or words to that effect. So, I think I've reached that point with my dead tach and I'll be calling the marina "experts" to take a shot at it. Still, it would be nice to hear what you all, who have any knowledge on this subject, can tell be about what you think it might be. I can, of course, still run the boat without a tach but....it's sometimes been my experience that a small problem (especially electrical) can be a symptom of a larger problem.
My system includes a Balmar voltage regulator (A MC-412, I think) installed by a PO which waits 45 seconds before sending a signal to the tach. This, as the manual says, allows the belts to seat and the engine to "lube up" before allowing it to start charging. So I know about this time lag. I also seemed to remember reading someplace that systems with a "multi-level voyage regulator" may sometimes keep a signal from going to the tach if the batteries are near a 100% charge. So...I turned off the battery charge at the dock for a day, while still running the usual stuff (fans, frig, lights) and started the engine to find the tach still dead.
I did take a reading of the voltage coming from the regulator while the engine was running and I found about .5 volts at idle and up to 1.8 and more when I revved the engine. In short, I tried just about everything I could think of short of actually testing the tach which I don't know how to do. BUt I suspect that the tach may be faulty.
Clint Eastwood once said in a movie, "everyman needs to know his limitations", or words to that effect. So, I think I've reached that point with my dead tach and I'll be calling the marina "experts" to take a shot at it. Still, it would be nice to hear what you all, who have any knowledge on this subject, can tell be about what you think it might be. I can, of course, still run the boat without a tach but....it's sometimes been my experience that a small problem (especially electrical) can be a symptom of a larger problem.
