Buzzer gone wild, will not go off

[shellone]

On a Searay 250 EC I have a Merc 7.4 with a Bravo drive; double propeller. No secondary gear lube container. The boat is on land since last August, everything was fine two months ago during last test. Today, 15 seconds after turning the key to 'on' a buzzer started (I say 'a' because I do not know if there is more of them). It did not go off. I double-checked the basics and since everything was ok I started the engine. Came just fine, cooling worked, just tried briefly switching in forward, worked perfectly. Oil pressure was good, water temp did not show any reading but risers were cooler than before engine start. Obviously there was enough oil and oil pressure, not overheating ... so what might cause the buzzer ? Turned off the engine, switched back to 'on', and in came right away. Disconnected the batteries, of course the buzzer went off, batteries back on, buzzer back on simultaneously. Does that drive have a sensor for drive lube level inside ? Would that be the first thing to check or in there something electrical that I might wanna tackle first ? Thanks for any idea or suggestion !

 

[alldodge]

Do you have a motor serial number?
If not that how about a year?

 

[shellone]

Do you have a motor serial number?
If not that how about a year?

Thank you for the attention ! The Engine Serial is 0F 079329, the drive is 0F050263.

 

[alldodge]

Look for a Tan/Blue wire on the thermostat housing and another either just below the distributor on rear deck of the block or on port side next to the oil filter.

The one on thermostat housing is water temp switch should be port side of housing

The motor has a oil pressure sensor and a oil temp switch. The switch and sensor can be on a Tee fitting. Look for the Tan/Blue wire.

Disconnect each one to see if buzzer stops. Once it stops you have found the bad one

 

[shellone]

Look for a Tan/Blue wire on the thermostat housing and another either just below the distributor on rear deck of the block or on port side next to the oil filter.

The one on thermostat housing is water temp switch should be port side of housing

The motor has a oil pressure sensor and a oil temp switch. The switch and sensor can be on a Tee fitting. Look for the Tan/Blue wire.

Disconnect each one to see if buzzer stops. Once it stops you have found the bad one

Thanks, again ! Located the wires, the oil pressure sensor in fact has a connection that looks corroded ... but disconnecting it, and the two under the thermostat, did not stop the buzzer. So I have three disconnected tan/blue wires, but the buzzer keeps going. Should I follow the wires and see if they have ground contact somewhere ?

 

[alldodge]

The only one left is the drive lube bottle but you said it doesn't have one. So with that try to see if the wire as grounded out somewhere.

One of the wires on thermostat housing goes to the temp gauge

 

[shellone]

I actually did not follow the tan/blue wires but tested that there is no contact between the ends and ground. I now have to figure out how to access the back of the cockpit which seems to be behind a toilet wall to see if it is the engine's buzzers or, possibly, some other buzzer. Thank you, again, it is very good to start this investigation knowing that the buzzer has no legitimate reason to buzz.

 

[alldodge]

Disconnected the batteries, of course the buzzer went off, batteries back on, buzzer back on simultaneously

If key does not need to be ON for the buzzer to still buzz then check your bilge pump, is it running, light on?

Being a 25 footer it might have a high water alarm. The high water alarm is a float switch that is not placed on the bottom of the hull, its up a bit higher

 

[shellone]

If key does not need to be ON for the buzzer to still buzz then check your bilge pump, is it running, light on?

Being a 25 footer it might have a high water alarm. The high water alarm is a float switch that is not placed on the bottom of the hull, its up a bit higher

The buzzer goes on only if I turn the key to on ... and I still have to install a high water alarm (which will have it's own buzzer. Trying to access the ignition key lock ... and the buzzer itself.

 

[shellone]

If key does not need to be ON for the buzzer to still buzz then check your bilge pump, is it running, light on?

Being a 25 footer it might have a high water alarm. The high water alarm is a float switch that is not placed on the bottom of the hull, its up a bit higher

Sorry to bother (you), again ... I seem to have found something that might be a high water alarm; it is to the front of the engine compartment, a black box, square shape, with a black round 'cable' or hose that leads through a conduit to where I cannot follow. Does that feel like a high water alarm ? And what can I do with it ? It is screwed with two small screws to the wall behind which I assume there is the fuel tank, the bottom of the box one inch over the bottom of the hull.

 

[alldodge]

Sorry to bother (you), again ... I seem to have found something that might be a high water alarm; it is to the front of the engine compartment, a black box, square shape, with a black round 'cable' or hose that leads through a conduit to where I cannot follow. Does that feel like a high water alarm ? And what can I do with it ? It is screwed with two small screws to the wall behind which I assume there is the fuel tank, the bottom of the box one inch over the bottom of the hull.

That sounds like a gas fume detector sensor
can you post a pic?

 

[shellone]

Thanks for your patience ! In the end I removed it, cut the wire and ... found out that the buzzer kept buzzing, the alarm would not work, the cable was ok. It has 12 V (black and red) and a brown wire that should trigger the alarm and the pump in case of high water. Shorting brown and red on the boat side makes the pump run, so the electrical is good, but the alarm does not work; shorting the sensors, or putting them in salt water, does not cause the brown wire out to carry any power. So I decided to remove the buzzer, but was confronted with the next problem. How to access it ? I had to remove the switch panel, with mirror, phone and so on find the buzzer, reach for it, follow the wires to it, brown and purple, cut one. Now the buzzer stopped, I can install a new high water alarm and connect an own dedicated buzzer. My only question now is: How do I access the space behind the panel? From the bottom there is no access, from behind there is the solid toilet wall, I see no obvious way to reach the 'cable area'. I know it must exist because I can see that it as been worked on before, just cannot find out how. Besides, the broken high water alarm is made in Italy ... called Quick, from Ravenna. Original ?

 

[alldodge]

Need someone with or has had a searay 250 EC or pics of yours. We cannot see what you have and without that we have no clue.

Sounds like the black thing was a electronic float switch for the bilge pump and not the high water alarm