MOERON

Port side sounds off as soon as you turn the ignition on and it seems worse when its warm. Gauges all look good and fluids have all been checked, what else? Some think it could be just not working right or have a short. It will also not stop once started but does stop after a minute or so.

Thanks

CMG

Moeron post this in Techical Q&A, I doubt it has anything to do with it being a Formula, it a Mercury issue. good luck

Treads

Moeron, posted a response in the other thread. Hope it helps.

mopower

When you checked the fluids , did you remember the drive oil bottle??? It got me one time

MOERON

Checked it.

Thanks

handfulz28

It's probably a sending unit for either:
drive oil
water temp
oil pressure
There's different sending units for the alarm and the gauges. I think it's relatively common for the drive oil sensor to go bad. Hopefully someone will chime in with a diagnosing procedure for you. I'd say disconnect the wire at each sending unit, but I'm not sure how the sending unit circuits work (normally closed or normally open).

CMG

speaking of the drive oil rez, if you still have the old round style get rid of them and get the late model square ones. In my old 311 mine leaked and caused the same alarm to go off. All of the round ones leak at some point.

MOERON

If it were a sending unit would it shut off after 30 seconds or so? Wiggling the key might help its hard to tell if that is stoping the noise or its just turning off on its own.

LAKE EFFECT

The warning system is a basic circuit that when shorted to ground from any of the senders it will sound the alarm. The circuit is easy to find, because all the senders have the same color wire attached to them(tan w/blue tracer). I would look at the oil sender first(around port side of motor toward rear oil pan area, that is the one that will trigger the alarm when the key is on, engine off, and stay on untill the engine has oil pressure. The temp sender is around the t-stat housing, probabally silver w/red on sender. Drive sender/bottle should have a weather proof electrical connection that is easily disconnected. Look for the tan blue wire at any of those locations, and disconnect each one, untill the alarm goes off.(the engine has to be running to check the oil sender).
Good luck. Scott

handfulz28

Sure. Take oil pressure for example: you've got oil, the gauge shows good pressure, but the sending unit/switch for the alarm isn't reading the same psi, hence a bad switch and the alarm goes off. Technically the alarm is activated by "switches" that just happen to look mostly like a sending unit. Oil psi activates the alarm below 10psi for example, water temp activates above 210, drive oil below a certain level; these levels are only examples I don't know what the actual activation points are.
I'd like to know what the actual activation points are myself. On my 311, if the port engine stalls after startup, the alarm sounds (oil psi is my guess). But it doesn't do it for the starboard side. I also got my starboard up to about 210 and the alarm never sounded. Maybe I need to check my starboard alarm wire....hmmm