Engine Alarm

[timc65]

I have a 2001 Merc 150 hp saltwater outboard 2 stroke. The engine ignition alarm is sounding continuously when turned on and running. It doesnt seem to be running hot, and the temp gauge is showing normal. What else could this be indicating. I've heard the possibility of low oil level, but I dont have a manual and have no idea how much should be in the tank.

 

[teejay1963]

Re: Engine Alarm

hello there! i have a 2004 mercury 150 xrs 2stroke on my bassboat. according to the mercury manual a continuous alarm is an overheat alarm. the intemittent alarm is for low oil pressure. my temp alarm went off last summer when my water pump impeller failed. check your water pressure and if you havent changed out the impeller then do so because these 150s overheat really easy without adequate water pressure to cool them.

 

[j_martin]

Re: Engine Alarm

Continuous buzzer is overheat. beep, beep, beep is coming from the oil alert.

A short, or a fault in the oil alert could also cause a continuous tone.

Either circuit grounds the alarm wire to sound the alarm. They come together at a terminal strip high and aft on the starboard side of the engine.

The overtemp sensor is a klixon cheapie on one of the heads.
The oil alert checks several signals and switches. If it's an EFI motor, the fuel filter is even involved.

Best bet is to get the engine maintenance manual for that engine and follow the alarm circuit troubleshooting in it.

hope it helps
John

 

[timc65]

Re: Engine Alarm

I dont think it is an overheat alarm, because it sounds even on a 100% cold engine as soon as I turn the ignition power "on." Secondly, is because you say the overhreat alarm is on the head, my noise is coming from under the dash, right next to the ignition unit. I will check the oil level and see how that looks.

 

[j_martin]

Re: Engine Alarm

I dont think it is an overheat alarm, because it sounds even on a 100% cold engine as soon as I turn the ignition power "on." Secondly, is because you say the overhreat alarm is on the head, my noise is coming from under the dash, right next to the ignition unit. I will check the oil level and see how that looks.

The overheat sensor is is on the head. The oil module is under the hood. They connect together where I said. If the sensor were shorted, it wouldn't matter if the engine was at the North pole, the buzzer would sound.

If you don't understand simple electrics, I can't help you.

John