oil tank sensor.

[brianbooker]

I have a 1994 60hp mariner. My oil warning horn started to go off. I unplugged the oil sensor and the horn stopped. I checked it according to clymer manual which said there should be no continuity with oil in tank. I found it had continuity and bought a new sensor, installed it and the buzzer still goes off. The socket the sensor fits in is dry, should there be oil in it? I drained all of the oil out of the tank and the buzzer doesn't sound, but when i add oil it does. It seems to be working backwards. Any suggestions? I checked the part number and it appears to be the right part, maybe it's bad too, but any help would be appreciated.<br /><br />Thanks, Brian

 

[kenneymc]

Re: oil tank sensor.

It sure does sound like it is working backwards. Have you done any work to it lately where you had to unplug and plug in some wires. Any way you could have gotten them backwards? I don't know this system or what type of sensor you have. Does it install in the top of the oil reservoir and operate on a magnetic float principle? <br /><br />I mean if you fill it and horn goes off then you empty it and horn does not go off, something is definitly backwards to me. Trace out the wires from sensor and make sure they are properly connected where they should be.

 

[schaiss]

Re: oil tank sensor.

 

[schaiss]

Re: oil tank sensor.

That sensor has two leads. One goes to ground on the engine block and the second lead goes to the lube alert module. With oil in the tank and the cover on tight, pull the lead going to the lube alert module. Using an ohmmeter, check the reistance of the sensor from the open connection of the sensor back to the ground on the block. With oil in the tank the ohmmeter should read infinite (very high) resistance. When the level in the tank goes low and the engine is running, the lube alert module "sees" the ground (a fault condition). Lube alert modules are wired to see the fault coming in, trigger the alarm on the instrument panel, and then ground out the coil to one of the cylinders (causing the engine speed to drop down.. but still allowing you to limp home).

 

[brianbooker]

Re: oil tank sensor.

I haven't done anything to the wiring. This just started to happen so i checked the sensor and replaced it with no luck. After messing with it some more yesterday here is what happened. With the oil tank empty the horn would not sound, then it suddenly decided it would sound on an empty tank. All i did was unplug the sensor and plug it back in. As i added oil to the tank the horn stopped, when the tank was about 2/3 full it started again. Checked the leads and the sensor circuit is closed to ground. I drained some oil out of the tank but it will not stop sounding. Guess i'll go buy another sensor and try again, but i'm starting to think it may not be the problem. Does anyone know how these sensors work? It installs in the bottom of the tank, in a small cavity, the cavity is dry (no oil in it) and i can't see a hole. Just curios as to how it knows there is oil.<br /><br />Thanks, Brian

 

[riverebel]

Re: oil tank sensor.

brianbooker,i have a 96 60 hp and it did the same thing.i replaced the warning module & the sensor.it ended up being the float inside the tank which is non-repairable.you will have to replace the tank.take the tank off & shake it & hold it upside down & i bet the horn stops.<br /> Charlie

 

[Fishallot]

Re: oil tank sensor.

I'm having a similiar problem. My sensor tested bad so I replaced it and it didn't solve the problem. I discovered the float inside the tank is stuck in the down position. I can free it up with a coat hanger but it keeps sticking back down. Like the previous poster stated the tank needs to be replaced. My parts shop didn't have one in stock so they said they can order it for me for $35.

 

[brianbooker]

Re: oil tank sensor.

Thanks guys, didn't know there was a float in the tank, I'll try that. <br /><br />Thanks<br /><br />brian