Borel Alarm electrical connection

[timjet]

I just installed a Borel raw water alarm in my twin engine ACMY. The instructions say to supply 12v DC power from a source that is switched on when the engine is on. I connected the supply voltage to the unit from the key on hot side of the ignition switch on the bridge of the port engine, ie power to alarm when the key is in the on position. Problem is if the port engine is shutdown for any reason, the starboard engine is unprotected unless I leave the port engine key switch in the on position. I could run an additional wire from the stbd key switch to the alarm the same as the port engine, but I don't think that would be a good idea, having a source of 12v to each engine key switch even with the engine shutdown. I guess installing a diode in the wire from each engine key switch would solve the problem, but wouldn't have a clue on how to do this. Any ideas??

Tim

 

[Alibuma]

You could pull the 12v from you blower. That should be on regardless of which engine is running. :thumbsup:

 

[timjet]

Yes that would work along with any other item continuously powered. However, I generally don't run the blowers continuously on my diesel powered boat.
My preference would be to power the alarm only when the engine(s) are running.

Tim