Audible alarms v's lights

[stravaig03]

Audible alarms v\'s lights

Hi, a previous post on this subject suggested a worn engine or poor oil which I doubt applies. Please - any other suggestions.

My audibe engine alarm sounds when the alarm lights don't light. Usually after a hard motor sail but sometimes from cold. The warning lights are functioning OK. The alarm is say 100% volume at start up and then maybe 25% when the engine is running at1000 rpm and silent at 1500 rpm. I've changed the fan belt to the yanmar type. I've checked the wiring twice. The oil level and type is ok. There is 'nt excessive smoke when the engine is running. The warning lights don't even flicker when the aud alarm is sounding at 25%. but even 25% is an agravating sound. I don't want to cut the aud alarm so any suggestions are welcome.

 

[KellysEye]

Re: Audible alarms v\'s lights

Probably a dumb qustion but could the audible alarm be alerting you to something that the lights don't - presumably what does what is in the manual.

Otherwise it sounds like a short somewhere, the fact that it doesn't always come on and varies in strength seems to indicate intermitent contact, sometimes just touching, sometimes full contact.

 

[stravaig03]

Re: Audible alarms v\'s lights

I've checked the manual but no joy. I've checcked the wiring in the sence that i've pulled and twisted looking for loose connections. I then had a sparky check and pronounced ok. I'm now thinking that one of the sensors or the horn has a fault. The big problem has been that when I'm ready to check the problem dissappears.
From a prev thread it appears that I can check each sensor by earthing one at a time when th problem occurs and I'll try that next.
Thanks

 

[KellysEye]

Re: Audible alarms v\'s lights

Certainly worth checking the sensors but if a sensor is faulty I would expect it to trigger both the sound and light alarms. I'm wondering if there is a fractured wire somewhere in the sound circuit that tests OK when the engine isn't running but begins to flex/short when the engine moves. My instinct would be to replace the wires on the sound circuit. Initially it doesn't need to be properly wired, just diconnect the old wires and attach new ones, if it works route the new wires properly.

 

[david_bagshaw]

Re: Audible alarms v\'s lights

JUST A THOUGHT

Is the audible bit getting sufficient voltage / adequate return /earth as our oil temps , bilge etc sensor warning system goes off on low voltage.