48MY Cat 3208 alarming sensors

[Boater Mike]

My port side 3208 siren never shuts off. I have good oil pressure and engine is cold. The entire engine is white, including wires, so its tough to trace out.

How many sensors are connected to this siren and where are they located? I can keep tracing but I'm hoping someone can save me some time. Thanks in advance!

-Michael

 

[McGillicuddy]

Alarm sounds at ignition and will shut down upon reaching minimum main engine oil pressure and gearbox oil pressure. So they are first two I would look at. The engine will alarm if cooling water goes over temp. It should not alarm at start up unless it is faulty. Check also the alternator for proper voltage. All in all one of the simplest alarming systems on a diesel engine. Four wires total.

 

[Capt. Jon]

Under the dash you have two Bosch ice cube relays that control the warning horn for port and starboard. Once a sensor trips the voltage to the relay it latches causing the horn to engage. Each engine next to the start key also has an alarm button. Pushing and holding this button allows you to silence the alarm while starting until the oil pressure is high enough to unlatch the relay. You can then release it. If this button is stuck in the normally on position it will make the horn stay on constantly. Also the Bosch relays will go bad and could stay in the lattached position. Otherwise you have something that is making current keeping the relay latched.