1997 Mercury 75 hp Alarm issue

[Searay D]

Hi everyone....could use some advise I have a 1997 Mercury 75 hp outboard with oil injection....I salvaged this off an aluminum Tracker boat....I pulled the complete harness.....When I start I get an audible chip......idol around nothing more...but when I throttle up the chirping persists... It's coming from a little red sensor that is under the dash wired to the ignition then to the engine...My question
1) is this a low oil alarm? ( I was trying to run the oil down so I could use Synthetic so its 1/4 full at this point) at what level does the alarm sound?
2) I traced the wire tan/blue/straight to the engine it goes under some modules and the a tan /blue/twist wire goes around the engine and into the head?
I'm guessing knock sensor?
The engine runs prefect...puffing a little smoke as it should...peeing strong...
Can someone please advise. Thanks

 

[Texasmark]

Tan or tan with a lt. blue stripe for over temp or light blue for oil are the alarm sensors. You have one for engine over temp and another for low oil in the reservoir in the engine. On some engines with the correct module, the over temp is a solid tone and the oil is intermittent beep beep. My manual shows the 97 to have the module so you should get the two different types of alarms.

The wiring harness near the control, or in the control box contains an alarm module. It gets 12v on one side from the key switch being on and ground if a problem exists on the other from the sensors mentioned. The sensor wire is pin 3 on the wiring harness (engine to control inside the engine) and the wire color is tan with a lt. blue stripe.

How low before it goes off? Probably down about 1/4 to 1/3. I never ran mine down to find out. Surely you would have some reserve when the alarm went off to give you time to get back to port safely.

Mark

 

[Searay D]

Thanks Mark ...I appreciate you taking the time to help me. I guess the easiest thing for me to do is pump out existing oil and refill with the Synthetic to see if that is causing the alarm....It's definitely a pulsing beep not a solid tone that I'm getting.It does speed up as I increase throttle... I can idle for 30 minutes and no chirping at all...Thats whats throwing me here.....perhaps I have a bad temperature sensor? I have a thermal heat sensor I guess i could check the temp with that. Do you know what the normal operating range should be? Also would I check at the head? or manifold?

 

[Searay D]

Thanks Mark ...I appreciate you taking the time to help me. I guess the easiest thing for me to do is pump out existing oil and refill with the Synthetic to see if that is causing the alarm....It's definitely a pulsing beep not a solid tone that I'm getting.It does speed up as I increase throttle... I can idle for 30 minutes and no chirping at all...Thats whats throwing me here.....perhaps I have a bad temperature sensor? I have a thermal heat sensor I guess i could check the temp with that. Do you know what the normal operating range should be? Also would I check at the head? or manifold?