Re: Add overheat warning light?
After having my engine (1989 Merc 5.7 Ski) blow an impeller, overheat and then blow the head gasket, I am wondering, is there a way to add a warning (idiot) light? I don't want the whole noisey warning horn system, just a light that came on at, say 200 degrees.
Actually it's quite easy to add a light for each alarm sensor (if installed)
The over-temp switch is simply a switch to ground. You connect it to a buzzer
and a light. When the switch is actuated by the over-temp it goes to ground and illuminates the light and sounds the alarm.
You NEED to keep the buzzer because the lights are not always easily visible in direct, bright sunlight...(I usually pull skiers in bright sunlight (warm days etc....)
You can also do the same thing for each sensor. (oil, drive lube, etc.) I am planning to have a separate light and buzzer for all three of mine.
If the buzzer only came on with an overheat, that would be fine, I just dont want it making a racket everytime I start the engine, which is frequent if you have skiers in the water.
The (low) oil pressure sensor will
always sound the buzzer when you turn the key on (
because there's no oil pressure until the engine turns)
So if you want the buzzer
not to sound when you start it you can separate the the sensors from the buzzer circuit so low oil pressure won't sound the buzzer....
I don't know which is worse though........popping a head gasket due to over temp or spinning a rod bearing, breaking a rod and driving it though the side of the block.......but hey....it's your boat...If you want to disable the alarms, it GO FOR IT!
Cheers,
)