Yanmar 'Waterproof' Warning Light

[Drumroll30]

I have a 1987 Yanmar 2GM20F with the type B engine panel. Yesterday when motoring back from sailing when I throttled down from 2700 to 1800 the "water proof" warning light and buzzer sounded on my engine panel. The strange thing is that the only warning lights that I am supposed to have are oil pressure, water temperature and charging. These three lights are on the right hand side of the 6 light panel, the other 3 should be blank. My manual showed nothing about the "waterproof" warning signal. After some internet research I've discovered that the water proof warning is only applicable to saildrives when a seal is compromised. My boat is shaft driven and all of my installations are un-modified and factory stock. Does anyone have any idea what might be causing this alarm to sound and how I can correct it?

[GordMay]

Evil spirits?

Sorry, I know it's not funny.

[DotDun]

It looks like the white-red wire in the harness is grounded somewhere.

Take the bulb out?

[Wotname]

DotDun is probably correct. The Yanmar wiring harness has all the wiring for all variants but of course in the non sail drive version, the switch is not present. The end of the Waterproof Switch wire is just loose in the loom.

Most likely the end of this wire is contacting the engine now (vibration possibly?); however it may be that the loom is chaffing at some point and the wire has been grounded at the chaff point. If so, the chaffing needs to be found and sorted out before more wires are damaged.

Try to find the source of the problem before say removing the lamp as it may be just the tip of the iceberg and an ounce of prevention is.. etc etc

[Drumroll30]

Thanks for the replies guys, I found the problem and you were both correct. The saildrive plug usually just hangs off the port side engine front. On mine I couldn't find it, when I did it was bent back (under the oil filter) and the white/red wire was tightly squeezed under the lock washer of the foward engine mount...amazing that it took 23 seasons to chafe through the shielding!
BTW I tried just removing the bulb but the alarm kept on ringing. Glad I found the source, engine alarms often go off at the worst possible time, even though I knew the saildrive one wasn't applicable to me the sound is still un-nerving.

[DotDun]

Originally Posted by Drumroll30

Thanks for the replies guys, I found the problem and you were both correct. The saildrive plug usually just hangs off the port side engine front. On mine I couldn't find it, when I did it was bent back (under the oil filter) and the white/red wire was tightly squeezed under the lock washer of the foward engine mount...amazing that it took 23 seasons to chafe through the shielding!
BTW I tried just removing the bulb but the alarm kept on ringing. Glad I found the source, engine alarms often go off at the worst possible time, even though I knew the saildrive one wasn't applicable to me the sound is still un-nerving.

I'm glad it's fixed!

After looking at the wiring diagram closer, yep, the buzzer will still sound with the bulb removed. I didn't study it close enough the first time. My first conclusion was the buzzer got it's ground thru the bulb.

[Wotname]

Thanks for the update and congratulations on hunting down the problem

[Ziggy]

You can put the saildrive connection to good use. Get a cooling water flow detector like this one and hook it up to the saildrive alarm wire.