what is the alarm for ?

[timv]

I have 1999 phantom 38 with cat 3116 engines. On the boat yesterday I turned the starboard engine ignition on to check the fresh water gauge - didn't start the engine and as well as the usual buzzer there was another siren alarm similar to a car alarm but I couldn't see any warning lights , and alarm very quickly stopped. Also when I was taking the boat round to the fuel bay, only a two minute journey, I could hear the alarm going off briefly again in the cabin although there was no alarm on the flybridge.
Volvo Paul has been a great help and I think he has nailed it down to a faulty exhaust overheat sensor just by what I've told him over the phone. He seems to remember the exhaust has a separate alarm , does anyone with a phantom have an experience of what this alarm may be and what the exhaust alarm sounds like ?
Oil pressure and voltage has been checked and is good.
many thanks
Tim

 

[BruceK]

Just an alternative possibility that it's not engine related. My cabin and engine bay bilge pumps are connected to a central alarm at the dash that will go off only once the ignition is activated. (Not A Phantom. nor SS btw) Sounds like a car / smoke alarm and very loud. (bilge pump is not affected by ignition, it's always live). I've had it go off intermittently once due to a connection fault when the boat was in motion. Gave me quite the scare.

 

[petem]

Just an alternative possibility that it's not engine related. My cabin and engine bay bilge pumps are connected to a central alarm at the dash that will go off only once the ignition is activated. (Not A Phantom. nor SS btw) Sounds like a car / smoke alarm and very loud. (bilge pump is not affected by ignition, it's always live). I've had it go off intermittently once due to a connection fault when the boat was in motion. Gave me quite the scare.

+1. My boat has three alarms (sounders) behind the dash.

1) Bilge pump
2) Seafire - on some boats these are integral to the display / override, on other boats there is an external sounder.
3) Engine alarms

I think it would be useful if the OP could track it down to one of these alarms or as he says another alarm for exhaust temp.

 

[jrudge]

Exhaust alarm. Go into engine room. The sensor is sticking out of the exhaust. The wire will have come off. I have it on squadron 58

 

[timv]

thanks for all the advise,as it turned out the starboard engine alternator has failed and I'm guessing this may have been the reason for the alarm although I don't understand why it would sound with just the ignition on and engine not started,but I imagine the fault was intermittent and maybe why it only went off only occasionally , anyway hopefully problem solved and thanks to everyone