I have a Yanmar 2QM15 in my '81 S2 9.2C, and after starting, the buzzer won't shut off. The oil pressure and water temp lights go off, the charge light stays lit (I think it's supposed to) and the engine runs fine. All fluids are OK, batteries are charged and full. Could it be a bad switch? It's somewhat intermittent at the first start, but once it happens, it continues. Thanks for any comments.
Buzzer alarm won't shut off
- Thread starter lthrneck689
- Start date
take the wire off the oil pressure switch and see if that stops it ..if so replace the oil pressure switch
ps that charge light should go off when the engine starts and runs...that may be your problem ...the buzzer has several connections on the plug and one goes the the charge light ....look and see if the light is going off when the buzzer is going off and on at the same time
ps that charge light should go off when the engine starts and runs...that may be your problem ...the buzzer has several connections on the plug and one goes the the charge light ....look and see if the light is going off when the buzzer is going off and on at the same time
Thanks! That was dumb of me about the light - of course it should go off. I'll try your suggestion today. I'm new to diesels. I just read somewhere that you should never turn off the ignition while the engine is running, or you could damage the alternator diodes. I do this all the time to shut down in conjunction with the kill switch. Also, if it makes a difference, I use new solar panels to charge the batteries, and they seem to be fully charged.
It's probably that simple. Crank the engine and check the alternator charging, (with solar turned off). Those panels are keeping the batteries charged, and the alternator more than likely has been called home to The Lord..
There is no ignition. The motor is shut down by stopping the fuel flow.
The only thing you are shutting off when you turn the key is the primary fuel pump, the engine instruments, and the glow plug availability - which is not needed after the engine starts.
If your charging cable is routed to the switch and an amp meter at the panel, and there is no bypass to the batts, then you may be damaging the alt if you shut the key while running.
The only thing you are shutting off when you turn the key is the primary fuel pump, the engine instruments, and the glow plug availability - which is not needed after the engine starts.
If your charging cable is routed to the switch and an amp meter at the panel, and there is no bypass to the batts, then you may be damaging the alt if you shut the key while running.
While all the idiot lights and buzzer share a common ground they are isolated from each other by diodes. So if all your lights are coming on I suspect that one of the diodes has gone bad and is allowing current to flow to ground when it should not.
The diodes are "inline" type and just look like a fat spot in the wire.
The diodes are "inline" type and just look like a fat spot in the wire.
Excitation Voltage
Doesn't the key also control the excitation voltage to the alternator that allows it to output?
Attachments
Re: Excitation Voltage
Well, I pulled all the engine access panels and the engine was drenched with water. Started the engine and the six inch hose from the thermostat to the riser was spraying water all over the engine, including the alternator. Wasn't able to check the charge flow, but my guess (as well as the Yanmar guy down the street) is that the alternator charge is being compromised. Checking the flow today after I replace the hose. Thanks, everyone!
Well, I pulled all the engine access panels and the engine was drenched with water. Started the engine and the six inch hose from the thermostat to the riser was spraying water all over the engine, including the alternator. Wasn't able to check the charge flow, but my guess (as well as the Yanmar guy down the street) is that the alternator charge is being compromised. Checking the flow today after I replace the hose. Thanks, everyone!
It depends on how the boat is wired. A sudden surge could occur in the same fashion as if the batts were disconnected, if there were no direct line to the batts(which there likely is).
It's something to look at, given the symptoms and OP's shut-down process.
Interesting.. I know that on the GM series Yanmars, the "Charge" lamp is not connected to the buzzer.. Had to do a little research and yes on the QM series engines, the charge lamp is definitely connected to the buzzer. I think that once the water damage is repaired the problem will go away for a while.
Well, the charge light and alarm issue is resolved. I dried everything out, cleaned off the rust, and the charge light goes out when the engine starts. BUT, now the engine is overheating - not much water coming out of the exhaust. Looks like either something is blocked, or the water pump isn't working too well. So far, I've checked the strainer and that's OK. I replaced the thermostat, and that's OK. No more leaks in the hoses. I removed the outlet hose from the water pump, and there's water coming out with the engine running, but it seems a little slow - maybe the impeller needs to be replaced. I think worst case is that there's a blockage in the exhaust, or in the engine cooling route (hope not!). Next move is to measure the water from the pump. I understand it should be flowing at about 4 GPM at 1000 RPM.
check the impeller/or replace it ...then if the problem persists you may have to pull the exhaust manifold and clean it ....i had to clean my old one about 4 years ago there was a lot of scale and rust in it ...the only thing to watch out for is that you don't get any holes inside the manifold......there are not many left for replacement if you do and there are no new ones at yanmar ...if there were they would be about $900.00...would be cheaper to just get a 2gm20f and replace the hole thing ....are you docked at harbor-town marina...
Woodster, yes, I'm at Harbortown. Found the problem. The 90 degree elbow going into the riser is blocked almost solid. I pulled the riser and tried to blow into the fitting - blocked. I tried removing the fitting, but it's in pretty tight. Don't want to risk breaking or cracking it, so I'm running some acid through it to clear it. Seems to be working. This was the cause of all my engine light issues - fitting clogged, split the hose going to the fitting, soaked the engine, alternator, etc., and caused overheating because of the block.
Thanks for everyone's help. Got quite an education.