Helm warning buzzer and light

[Carlhere]

Hi Folks,
I own a 37 foot international 1985. twin diesel 6-71. This has a upper helm station on the bridge and lower helm station in the salon.
I had when moving a warning light and buzzer on both stations upper and lower for the port engine.
Immediately I check coolant temperature, Oil pressure, and transmission pressure and all were within specified limits. I had then shut the engine down and removed the engine cover. I checked for anything that may have been abnormal and in addition checked all the fluids anyway to confirm. All levels were good and right where they should be.
After about 20 minutes I started the port engine again and the buzzer and light were not on and there were no warnings on the helm stations.
These warning lights and buzzer is also active when activating the ingnition switch before starting the engine and shuts off as soon as the engine starts. And comes on again when the engine is shut down and will remain on until shutting the ignition switch to the off position.

Can anyone with any experience with this model Trojan tell me what other causes would activate the warning light and buzzer when the engine is running????
Any help would greatly be appreciated.
Thanks Carl

[gettaway]

I would bet you have a faulty oil pressure switch or temp switch in the alarm circuit, which are typically wired in a series and are not the same sensors that send readings to your gauges. I am not certain with a DD, but it may be a good place to start. Also, do you have direct reading gauges for oil pressure, Temp and voltage/ amp somewhere in the engine room to reference when you have an alarm?

[Carlhere]

Hello Gettaway
There are no guages in the engine room for niether of my engines to reference. They are only on the upper and lower helm stations guages.
However when the port alarm signaled I did reference the upper and lower stations to compare readings. They have given the same readings for the port engine that everything was ok.
Something else must have triggered the alarm and I'm trying to get all the information I can as to what systems will trigger the alarm other than oil pressure, temperature, volts, transmission pressure. There must be something else?
In this case, if this should happen again I would ground the oil pressure, and temperature wires one at a time and see if the alarm shuts off. If so I guess that would condem the sensor switch.
Even so I am hoping someone will know if anything else or any other system is connected to the alarm that would trigger it.
Carl

[prowlersfish]

grounding will turn on the buzzers . what was the oil pressure at the time ? The oil pressure switch for the buzzer may not be part of the sender . ( same goes for temp ) . I seen some 671 with 15 psi switches turn on at idle because the pressuser drops below 15 .Some of them don't carry a lot of pressure .

[Carlhere]

At the time the buzzer and light alert was triggered we were up on plane. The oil pressure was 45 and the coolant temperature was 160