Alarm buzzer

[Paulus]

My alarm buzzer works intermittently when I turn the key to heat the glow plugs. Need some ideas.
Thanks,
Paul

[Ken Juul]

Dirty or loose connections in the wiring.  Clean and tighten the connections (key, buzzer & grounds) behind the engine panel and at the engine.  If your wiring harness has terminal strips check them also.

[Paulus]

Thanks Ken for the ideas.  Do you know where the oil sending unit is located on the M25XP?
Paul

[Ron Hill]

Paul : Go to Radio Shack and they sell the 12v DC buzzers. I'd just replace that 21 year old one!!  

The oil pressure switch is just above the starter solenoid on the port side of the engine.  A little tight to get at, but I've done it a number of times.  I also wrote an article in the C34 Mainsheet tech notes on that Oil Pressure Switch.  A few thoughts

[Stu Jackson]

Thanks Ken for the ideas.  Do you know where the oil sending unit is located on the M25XP?

Paul, there are TWO sending units on your M25XP.  The one for the idiot buzzer is right above the thermostat on the housing, and if you actually have an oil pressure GAUGE, then it's way back aft, port side, down low, under the starter and the alternator, just forward of the port side aft engine mount.

[Ron Hill]

Paulus : On my old 1988 M25XP (bronze color made by Oshkosh) I had the oil pressure switch located under the coolant reservoir on the port side.
 
I understand that if you had a gage with an oil pressure sender, a hose screwed into that same hole and came out and had two connections (a "T").  One for a switch (idiot buzzer/light) and the other to a sender for the gage.  I'm not too sure how this hose was secured as I never had a gage. 
I Just had the switch with a buzzer which I also wired into a red light on the engine instrument panel.  No Oil pressure -- I got an audio + a visual alarm.
A few thoughts.   Hope this helps

[Ron Hill]

Early Boats : I just remembered that there are probably sill some C34s out there that probably still have the silvery engine instrument panel.

Those boats had two yellow warning lights :
One for the oil pressure and One for the starter engage. 

Guess they must have had some problems with the starter staying engaged??   

[Paulus]

I have the bronze color engine.  I do not have oil pressure gage(sorrow).  I have the audio + visual alarm.  I have gone through some of the wiring today and the audio alarm worked, tried it 3x during the day.  Put new ends on all of my battery cables.  I appreciate all of the input and hopefully it is working.  I will go out again this week and try it.
Thanks,
Paul

[pablosgirl]

Hi Ron,

I have and older 34 (1988, hull 551) with the silvery engine instrument panel with the two yellow warning lights.  The oil pressure one is near the bottom center of the panel and the other between the key switch and the right/forward edge of the panel.  I had no idea the the other was a starter engage light.  Mine stays on as long as the key switch is on.  When the engine starts the oil pressure warning light and the buzzer go off.  How does the starter engage light work (theory of operation)??  Any trouble shooting ideas?

Thanks

Paul