nigel1
Well-Known Member
Appear to be having issues with the alarm module, hopefully someone here can confirm or point me in the direction of any other possible causes.
Bit of background
Boat is a Beneteau 473 with a Volvo Penta TMD22, and originally fitted with the standard 60A Valeo alternator (regulator set point about 14V). The alternator output was to a split charge diode with three outputs.
I later fitted an Adverc external alternator (was at a very reasonable price), and I replaced the split charge diode with a zero volt loss charge splitter from a well-known UK company.
Just recently, I replaced the alternator with an uprated version, 100A output with the regulator set point at 14.4V.
At this point, everything seemed to be working OK.
Here is where it starts to go wrong. I replaced the Adverc with a different external regulator (from that well known UK company), as this supposedly would boost bulk charge to 14.8V, and a float charge of 13.6V. (In fact, the voltage will only drop down to the set point of the internal regulator, in this case 14.4V)
On starting the engine, the alternator started to output, but the voltage kept climbing until the external regulator tripped out on high voltage.
I contacted the maker, who had me check all sorts of voltages at different points, and while doing this, he informed me that there was also an issue with the split charge unit, as I was getting battery voltage on the input side with the engine off. (This turned out to be incorrect, as when I called them later, and spoke to a more senior person at the company, I was advised that there should be battery voltage on the input terminal)
The external regulator was returned for testing, and I was advised that it was malfunctioning, and they sent me a replacement (not yet fitted). It was also suggested that it would be better to replace the zero volt loss splitter with a regular split charge diode. If the external regulator sense connection is fitted to one of the output terminals of the splitter, the external regulator would boost bulk charge voltage to 14.8V at the battery, and when it dropped to float, the batteries would be seeing something like 13.9V
After removing the external regulator, I went to start the engine, and noticed that with the ignition key in position 1, only the Oil Low Pressure light came on, the Alternator and Water Temp warning lights did not come on. Turning the key a little further to engage the glow plugs, then all the lights came on. Engine then started, and alternator appeared to be working OK, (as observed on the battery monitors) Stopped the engine, and then put key back to position 1, and went to check the voltage on the alternator D+ terminal, only 9V. While doing this, an alarm went off, and it was the Low Oil Pressure alarm
Following week, I replaced the charge splitter with a split charge diode. Went to start engine, with key in position 1, Oil Light brightly lit, and the Alternator and Water temp light were on, but very very dim. Pressing the alarm test button made no change.
I checked the voltage at the D+ terminal, only 4V this time. While doing this, I expected the oil pressure alarm to sound as it had done the previous week, but this time no alarm. Started the engine, no output from the alternator, and a few seconds later, Alternator alarm sounds and the light flashes (bright, not dim) . I then briefly bridged one of the split charge output terminals to the input terminal to put battery voltage on the B+ terminal, and the alternator kicked into life.
Stopped the engine, checked voltage at D+, still 4V. Left the engine off for an hour, and then started it again, and this time, the alternator started to output immediately.
I have managed to get hold of a used, and supposedly working alarm module, and plan to fit this next time to the boat, but does all of the above point to a malfunctioning alarm module, and also, can someone explain, how come the alternator started to work the second time I started the engine.
Have included some wiring diagrams for earlier threads of a similar nature
Bit of background
Boat is a Beneteau 473 with a Volvo Penta TMD22, and originally fitted with the standard 60A Valeo alternator (regulator set point about 14V). The alternator output was to a split charge diode with three outputs.
I later fitted an Adverc external alternator (was at a very reasonable price), and I replaced the split charge diode with a zero volt loss charge splitter from a well-known UK company.
Just recently, I replaced the alternator with an uprated version, 100A output with the regulator set point at 14.4V.
At this point, everything seemed to be working OK.
Here is where it starts to go wrong. I replaced the Adverc with a different external regulator (from that well known UK company), as this supposedly would boost bulk charge to 14.8V, and a float charge of 13.6V. (In fact, the voltage will only drop down to the set point of the internal regulator, in this case 14.4V)
On starting the engine, the alternator started to output, but the voltage kept climbing until the external regulator tripped out on high voltage.
I contacted the maker, who had me check all sorts of voltages at different points, and while doing this, he informed me that there was also an issue with the split charge unit, as I was getting battery voltage on the input side with the engine off. (This turned out to be incorrect, as when I called them later, and spoke to a more senior person at the company, I was advised that there should be battery voltage on the input terminal)
The external regulator was returned for testing, and I was advised that it was malfunctioning, and they sent me a replacement (not yet fitted). It was also suggested that it would be better to replace the zero volt loss splitter with a regular split charge diode. If the external regulator sense connection is fitted to one of the output terminals of the splitter, the external regulator would boost bulk charge voltage to 14.8V at the battery, and when it dropped to float, the batteries would be seeing something like 13.9V
After removing the external regulator, I went to start the engine, and noticed that with the ignition key in position 1, only the Oil Low Pressure light came on, the Alternator and Water Temp warning lights did not come on. Turning the key a little further to engage the glow plugs, then all the lights came on. Engine then started, and alternator appeared to be working OK, (as observed on the battery monitors) Stopped the engine, and then put key back to position 1, and went to check the voltage on the alternator D+ terminal, only 9V. While doing this, an alarm went off, and it was the Low Oil Pressure alarm
Following week, I replaced the charge splitter with a split charge diode. Went to start engine, with key in position 1, Oil Light brightly lit, and the Alternator and Water temp light were on, but very very dim. Pressing the alarm test button made no change.
I checked the voltage at the D+ terminal, only 4V this time. While doing this, I expected the oil pressure alarm to sound as it had done the previous week, but this time no alarm. Started the engine, no output from the alternator, and a few seconds later, Alternator alarm sounds and the light flashes (bright, not dim) . I then briefly bridged one of the split charge output terminals to the input terminal to put battery voltage on the B+ terminal, and the alternator kicked into life.
Stopped the engine, checked voltage at D+, still 4V. Left the engine off for an hour, and then started it again, and this time, the alternator started to output immediately.
I have managed to get hold of a used, and supposedly working alarm module, and plan to fit this next time to the boat, but does all of the above point to a malfunctioning alarm module, and also, can someone explain, how come the alternator started to work the second time I started the engine.
Have included some wiring diagrams for earlier threads of a similar nature
