Re: Mariner 90hp Warning Buzzer
Welcome to iboats, Pete.<br /><br />Are you getting the beep beep beep oil warning or the beeeeeeeeep overheat warning? Here's a brief explanation of the components...<br /><br />The overheat sensor grounds the alarm when the cylinder head temperature gets too high. They rarely fail except from physical damage from extreme overheating. The fix for that is to replace the overheat sensor.<br /><br />There is a float in your oil tank that sends a signal to the warning module when the oil gets low. Some oils could be too thin to float it high enough, but that seems to be rare. There is a magnet in the float that trips a magnetic switch. Sometimes that magnet dislodges, or the float absorbs enough oil to keep it from floating. That would give you a beep beep beep as soon as you turn on the key. The motor doesn't have to be running. The fix for that is to replace the oil tank. You can't get any internal parts for it.<br /><br />The warning module takes the signal from the oil tank sensor and produces the beep beep beep. They can fail so that they produce no sound, but much more frequently they will sound a steady beeeeep on the alarm when they fail. You can usually tell it's going bad if the tone is unusual or if you sometimes hear faint sounds coming out of the alarm. A failed warning module will usually sound as soon as you turn the key on. The motor doesn't even have to be running. The fix is to replace the module.<br /><br />The alarm itself is also designed to sound if it fails. It could fail to sound at all, but like the warning module they usually sound a beeeeeep if they fail. Like the warning module, the alarm will sound as soon as you turn on the key and the motor doesn't even have to be running. The fix is to replace the warning horn.<br /><br />Finally there is the wiring that connects it all. You could be getting a short on the alarm circuit from a pinched or damaged wire. The alarm has 12v positive to it anytime the key is on. The warning system grounds the other side to complete the circuit. There could be a problem with a tan/blue wire anywhere between the overheat sensor and warning horn. There also could be a problem with the blue oil tank float switch wires although I think that would be less likely.<br /><br />Intermittent problems are tough to track. I have seen the problems described in about the same frequency, so I can't really say which is the most likely to be causing your problem. Hopefully these descriptions will help you narrow-down the possibilities.<br /><br />Of course there is also the possibility that the warning system is working perfectly and is sensing an actual problem. I used to live where there was a weed line several yards out off the pier. We couldn't get to the lake without crossing it. Situations like this can cause clogging of the water intakes on the gearcase occasionally. A weak water pump or an internal blockage could also do it. Maybe a sticky thermostat. And the oil level in the tank could be such that you get no alarm with the motor trimmed fully down, but sound as you trim it up. I'd check those possibilities first. Good luck.
