Re: Mercruiser 165 IL 6, 1979 Engine Alarm
Howdy,
Most all of the old oil pressure alarms are simply an oil pressure switch that closes at less than some predetermined low pressure like 5-10 psi.
There's also a hi temp sensor (switch) that closes at some high temp like 220 or above.
BOTH switches are usually connected to a single wire that goes to the instrument panel. (so either low press or high temp will "ground-out" the wire)
The other end of the wire is connected to the "buzzer" which is also connected to switched power (12v DC) so the buzzer is powered any time the "key" is on.
If you can find the buzzer, you can replace it with just about anything you want including an idiot light.
Here's a bunch of examples.
Understand that the "buzzer" will sound whenever the temp is high or the oil pressure is low. (Since BOTH are connected to the same wire)
If you want a different sound for each alarm, you'll have to run a separate wire for each sensor and use a slightly different sounding "buzzer".
I am thinking about doing just that for my temp, oil press, and drive lube reservoir.
Cheers,
Rick
