43 DCMY Systems Monitor Alarm

[Triskele]

The starboard engine System Monitor Alarm is sounding after stopping the engine and turning off the ignition key. Alarm stops sounding when engines start up. Both eng temp and oil press are in normal ranges when running and the alarm doesn't sound when engine is running. Has anyone experienced this or know why this may be happening? Both oil and pressure switches operate in Normally Open positions. Alarm is sounded when they close. Could there be a short some where? If so, where? Could this problem be caused by a failing temp switch that is remaining "closed" (don't believe it is the oil pressure switch...tested and seems to be workiing). If temp switch was stuck in closed, wouldn't the alarm sound when engine was running? Also checked fuse. It is fine.

One last thing, the fuel switch sends current to the oil press and temp switch when engine starts running. Fuel switch is a NC (normally closed) switch. Is it possible it is remaining closed when ignition switch is turned to off? Any idea how to test?

 

[Triskele]

Additional information on my problem. I have a Glenndenning Synchronizer on board. I was out over the weekend and used it. I also anchored overnight in a heavy rain. It appears water got in through the side windows of the salon and also up on the aft deck. When I switch on the Glenndenning Synchronizer (ignition turned off), the starboard alarm alert stops. When I turn it off (push in the switch) it starts again. Also, my Naiad Stabilizer monitors turn on when ignition key is turned off, but turn off when I pull out the Glenndenning Synchronizer. This all started after being out overnight in the rain. Did not happen before. I'm guessing this may have to do with a water short in the wiring and electronics, but just wondering if it may be something more obvious.

I have noticed there have been a few views of this thread, but no responses so I am guessing after reading this you are all probably thinking my problem isn't obvious and is more likely to be a rat's nest of possible electrical problems. I am beginning to feel that from the deafening silence on this thread that the chances of hunting down and troubleshooting this problem may be beyond the scope of this forum and as well beyond my own capabilities. However, I will keep you posted if I can solve this mystery.

 

[sgharford]

Good Morning. Just read your thread as I'm riding the train to work. I too have a 43dc with original engine alarm for low oil pressure and high water temp. The alarm is suppose to go off when the engines have stopped - no oil pressure = alarm. The alarm goes off when you start the engine. Assuming you have the original alarm with 4 orange light bulbs and selector switch (with all markings wiped off the aluminum panel from age), 2 of the 4 lights should come on when you flip the panel on. Those are the starboard and port oil pressure sensors. They should go off when you start the engine/ build oil pressure. Note that the 5 position rotary switch is for testing each of the 4 sensors independently and if don't leave in normal operating position (think turned all the way clockwise) then one light/buzzer will stay on all the time as it's in test mode. Good luck with her, mighty fine vessel.

 

[Vincentc]

My alarm went off sporadically while the engines and keys were off. The cause was a short in the fly bridge alarm box.

Check and clean the wiring in both alarm boxes.

Regards

 

[sgharford]

Mine go off with or without the keys turned in ignition since I've had her. Always figured alarm panel was wired independently of the ignition switches and why this was the case. I've always flipped the panel on before starting, saw the oil pressure lights and heard the buzzer, then started each engine and waited for buzzer/lights to go off (confirming oil pressure on engine gauge) - signaling at least the oil pressure alarms are working as they should. If I was a betting man I bet someone goofed with that rotary selector switch on the alarm panel and it's in the wrong position and why things are all of a sudden acting erratically.

 

[Triskele]

My alarm went off sporadically while the engines and keys were off. The cause was a short in the fly bridge alarm box.

Check and clean the wiring in both alarm boxes.

Regards

Hello Vincent...Thank you for your reply. I suspect you may be onto something. I was overnight in a heavy rain and there was leaking on board. Also, had a very humid and moist summer (seemed to never stop raining). Although I am undercover, not sure that is protection from the kind of humidity we had. In fact, there were times I came into the boat (don't like to run A/C much during day) and there was dripping from the head liner and some moisture on my dinette. I'm thinking the possibility of a short is quite high. However, I have other complicating and mitigating issues that I'm working through (ignition switch was wired wrong making power to each post, thus shorting the ignition and never being able to turn it to off, thus could start starboard engine when switch in either on or off). Bennett leveler motor just starts out of the blue sometimes and starts running. Then shuts off. Wierd. Could be a short there as well. Will post more once I get done trouble shoooting and things sorted out. Can't tell you how much I hate electrical on old boats. Am about ready to pull electrical on all nonessentials. Get to the bare bones. KISS (keep it simple...).

 

[rwappleton]

Ours is a 79 43 DC and the alarms come on when I turn the respective ignition on, and silences when the engine is running and has oil pressure.

When we shut down the Alarms comes on when the oil pressure drops below target level (what ever that is) and stops when I turn the key off.

I check them each time I start and check all 4 switches on a regular basis.

Hope this helps........