I have 2001 man D2848 LE 403 engines all mechanical with the older style alarm lights buzzer screen pictured below. I see where they are plugged into the back of the screen/ display whatever it is actually called. On the port engine all of the lights and when a warning has happened the buzzer sounds and the light flashes etc. However when running sometimes the GREEN engine in operation mode light will be on for a while then off for a while. More so off at 1900-1950 rpm's. But certainly it is intermittently operational. I have check the connection to the back and made sure all was good, does this unit plug into the big black boxes in the engine room, or where else do I need to check and see what is going on along the line, I assume it to be a bad ground/loose connection somewhere. Any input is appreciated, thank you
Or, could you have a real problem and something needs attention. If you have that big MAN box for each engine, Yes, that is the next connect point for that panel. Mechanical, Electronic, MAN sensors do seem to have a strange fail pattern. Most senders are DanFoss devices. Reliable as heck everywhere,,, but on a boat engine.
During my big winter maintenance.... cooling system, injectors, valve lash a fuel leak on the injector lift pump on the return line, and some misc other parts that were "ready to break" I took each sensor connection off for coolant temp, oil pressure, coolant level, and cleaned up the connections and re-ended a couple wires and gauges have been spot on. I also added 2 mechanical oil pressure gauges direct from the engine block to the mounting plate, piece of mind in case of a crazy fault or alarm or sensor failure etc. The way the green engine on light is happening I am thinking that is a loose ground somewhere maybe before it goes in the big black boxes but don't know where to start looking. When I use the test button all lights glow as they are supposed to. I am more mechanically inclined than electrical for sure and a bit worried about unplugging that connection on the big box, thinking it probably has not been apart since the boat was built in 2001. Thinking I will spray some penetrating oil on the connection before trying to take apart.
for real.....? why does it seem you are against doing scheduled maintenance and being pro-active on making things right ? This issue has been happening since I have had the boat. I may not have a man tech certified patch, however what I did on the engines is all pretty straight forward and not overly complicated at all. Most of the items were just big heavy and awkward. if I would have "deferred" this service until the "don't mess with it if it aint broke" then things get really bad and won't don't come apart and more damage is done by doing reactive repairs versus preventative. I am posting as I am curious if anyone knows where the "engine in operation" green light from the panel or display or whatever it is called comes from on the engine, like maybe someone can chime in and say oh yeah it is by the flywheel etc. I will find out, I will post when I do but again just looking for some feedback that maybe someone has had the same issue and they say "yeah man its right there easy peasy etc."
for real.....? There are four different failures on a boat; Lack of maintenance Poor installation Stuff does fail Induced When did we start talking about scheduled maintenance? In my 20 years of learning and helping on this forum site, when I read of folk working on their boats, taking things apart and making things right,,, THEN asking why it does not work there after, it is very easy to start imagining the Induced failure mode. Neither do I. Started working on them only 15-16 years ago. My fastest and best lesson on MAN engines, If it is not broke, don't fix it. This greatly reduces the Induced failure mode. We know this from where? Until this comment, I did not know,,,,, for real...
It could be as simple as a fault with the LED or it's connection. Can you switch the port and starboard indicator panels to localize the fault to the panel itself (or not)? Also, when checking plugin connectors, pay particular attention to the pins and receptacle sleeves IN the connectors. I have found faults where the locking tab on connectors were not fully engaged and the pins or sleeves were pushed back and making a poor connection from manufacture. Problems with the connections appeared later in life after vibration or tarnish affected the quality of the contact. I'm with you; small innocuous failures can be the precursor to larger problems, like the engine actually being no longer in operation when the light goes out!
d_meister.... I'm with you; small innocuous failures can be the precursor to larger problems, like the engine actually being no longer in operation when the light goes out! The green light will be out for good 15 minutes sometimes while running at cruise 18k-1950 ish then will come back on for a while, then out for half hour or so etc. I will definitely check the connections again at the helm. So the engine is in operation, I was also worried that if that light was out is that particular green engine in operation light a "master power" on so to say for the entire panel. Like if that light is out is the panel not going to show any other alarms. Answer to that is no, yesterday I had a coolant level sensor failure alarm go off while the "engine in operation" light was out. So that tells me the engine in operation is isolated from others in panel, at least for the coolant level sensor failure warning. I am going on record sayin that I do NOT know if other alarms in the panel will work without the green light on. I am only assuming......phew So what I will do to fix the sensor failure is not just put in a new sensor as it has 2 per engine but take the connection off clean the contacts and put back together on each sensor as the warning does not indicate which sensor is having a failure. I did this on the starboard plant and that cured my sensor failure alarm I had in the past. I messed with it cuz it was only kind of broken. I have also cleaned all of the connection points on the other sensors and they have been not acting up at all like previous oil pressure gauges etc. The connections that still worked but had questionable terminal connections got new connectors, solid and strong instead of almost broke but still working for now. I am hoping that someone knows where the engine in operation gets its signal from the engine then to the black box as I am pretty positive the problem lies from within that connection at engine and anywhere in between to the helm. Thanks for any positive input
