system pretests

[laughingbass]

Mercury tracker marine 115hp serial # OG556411<br />I rev'd engine up while running boat in water and still on trailer. The warning horn came on with a continuous pulsating beep-beep. I shut off engine hoping it would reset. Later I disconnected battery, also trying to reset warning horn. Warning horn will not reset. Continuous pulsing beep when key is in on position. I changed impeller. What is being checked when key is in on position, besides oil sensor. Is there a poppet sensor , thermostat sensor, etc.

 

[KCLOST]

Re: system pretests

You have an overheat sensor and an oil injection sensor.<br /><br />A continuous beep, would indicate an overheat condition. A beep,beep,beep,pause,beep,beep,beep,pause, etc. would indicate a oil injection problem.<br /><br />Does this happen immediately after starting the motor or after turning the key to the on position, or later after the motor has warmed up.

 

[laughingbass]

Re: system pretests

Happens when I turn key to on position and continues after I start engine.

 

[KCLOST]

Re: system pretests

Ok, you're in good shape, considering it not an engine overheat problem...<br /><br />You have a sensor failure (MOST LIKELY)....<br /><br />The overheat sensor is mounted at the top of one of the cylinder heads, I'm a V6 guy so look just under the top spark plug. I would remove it and OHM test it out (follow you're manual, get one if you don't already). Check the wire to make sure it is not grounded (worn) through. <br /><br />Let us know... You can also disconnect it to run a test. Follow the lead from the sensor to the screw that holds it to a junction on the starboard side of the motor. Remove the lead from the juction (but make sure it doesn't touch anything to ground after you do it). After that start the motor. If the alarm goes away, it's got to be the sensor going bad... <br /><br />Don't run on the lake without it however, get it replaced....

 

[laughingbass]

Re: system pretests

I replaced the rev limiter module (RPM limit module), thinking that was the module going out, based on circumstances that caused problem. However, it appears to be oil sensor module. I disconnected ground lead to the oil sensor module and warning horn stops. A mechanic at a boat dealer told me that this test meant nothing. He said it was propably the float in the oil tank was not working, and I would need to replace oil tank. He said to disconnect one of the two blue wire leads and if the horn stops then it was the float (valve?) in the oil tank. Is this possible.

 

[riverebel]

Re: system pretests

yep......