Oil alarm mercury 175 saltwater series

[gohawks688]

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Ok guys I am having an oil injection alarm on my 1999 mercury 175 two stroke salt water series. If needed I can provide serial number. Upon start up it has a continuous beep beep beep alarm. I have a factory service manual and have trouble shot the following items.
1. Oil reservoir float sensor does not have continuity. This is what the manual says it should be.
2. Checked the voltage at the coil tied to the alarm module with DVa adapter. It checks out within spec.
3. Removed oil pump and inspected plastic crank gear. Gear looks to be in good shape.
4. While trying to trouble shoot the oil pump rotation sensor the first step is to ensure that the alarm module is supplying 12+/-1 volt to the rotation sensor. I'm only getting 9 and change. I don't think I can reliably check for the 5v pulse every two revolutions per the manual of the sensor isn't getting proper voltage. Is this a sign that my alarm module is on the fritz? That is the way Im leaning.
I am having trouble sourcing parts for the module. The part number on the side of the module is 41470a23, I can not find a perfect match for the life of me. I can find 41470a25 and 26 modules. Marine engine also lists the a26 module for my engine. Does anyone know the interchangeability on these modules?

Thanks for the help....

 

[Faztbullet]

The AXX number at the end is just a series number. As long as part# is the same it will work.

 

[gohawks688]

Awesome that's good to hear. They are pretty spendy so I wanted to know I had the right part.

Does it sound like I am on the right track replacing the module itself?

 

[Dukedog]

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Ok guys I am having an oil injection alarm on my 1999 mercury 175 two stroke salt water series. If needed I can provide serial number. Upon start up it has a continuous beep beep beep alarm. I have a factory service manual and have trouble shot the following items.
1. Oil reservoir float sensor does not have continuity. This is what the manual says it should be.
2. Checked the voltage at the coil tied to the alarm module with DVa adapter. It checks out within spec.
3. Removed oil pump and inspected plastic crank gear. Gear looks to be in good shape.
4. While trying to trouble shoot the oil pump rotation sensor the first step is to ensure that the alarm module is supplying 12+/-1 volt to the rotation sensor. I'm only getting 9 and change. I don't think I can reliably check for the 5v pulse every two revolutions per the manual of the sensor isn't getting proper voltage. Is this a sign that my alarm module is on the fritz? That is the way Im leaning.
I am having trouble sourcing parts for the module. The part number on the side of the module is 41470a23, I can not find a perfect match for the life of me. I can find 41470a25 and 26 modules. Marine engine also lists the a26 module for my engine. Does anyone know the interchangeability on these modules?

Thanks for the help....

did ya check voltage to tha module (supply) on purple wire?

 

[gohawks688]

Yep the purple wire has 12 volts

 

[Faztbullet]

Also swap the signal wire (green) off switchbox to a different cylinder.

 

[gohawks688]

I tested the green wire At the coil with DVa meter per the manual and it was withing spec.

 

[Dukedog]

do ya get tha "self check" beeps BEFORE it goes into alarm beeps?.. if ya plan on keepin' tha oil injection with all its sensors i would take a chance on a used one off ebay before i bought new.... that part is not known for common failures (but do fail on occasion) ..... we've given and/or thrown away lots more good ones, over tha years, than i can count.....

 

[gohawks688]

do ya get tha "self check" beeps BEFORE it goes into alarm beeps?.. if ya plan on keepin' tha oil injection with all its sensors i would take a chance on a used one off ebay before i bought new.... that part is not known for common failures (but do fail on occasion) ..... we've given and/or thrown away lots more good ones, over tha years, than i can count.....

I do get beeps when first turning the key. Now that you mention it though it seems like the start up beep sounds different. It may be in my head however. It doesn't seem to be the normal cadence (i think it was four beeps) but more like the alarm itself (a rapid beep for about a second then stops.)

Ok so i bought this module and installed it. https://www.ebay.com/p/1345154650
everything went smooth except that there was a splitter provided for the blue wire that goes to the oil plug cap sensor. the splitter would allow for two wires to the sensor. my reservoir only has one. I didn't use the splitter and hooked up the wires to all the proper colors.
started it up and it still alarms!!!!! arg.

Back into the trouble shooting per the manual. The rotation sensor is now getting 12v+/- 1 v as per the manual. It was only getting 9v from the previous module and that is why I ended up swapping the module.

The manual states " turn ignition on. Rotate engine using pull rope. check output voltage at the blue/white wire. Output voltage should peak at 5+/-1v and then drop to less than 1v during every 2 revolutions of the engine. If no voltage is present then either the sensor is faulty or the drive system is broken" I do get 5v and it does drop off to less than 1v but IT SEEMS TO HAPPEN MORE OFTEN THAN EVERY TWO REVOLUTIONS. Am I understanding the manual correctly that if it happens more often then my sensor could be faulty?
Any ideas guys?

 

[gohawks688]

I did more testing on the oil cap sensor. the manual states " disconnect both low oil sensor leads. There should be no continuity between the leads. If continuity exists then the sensor is faulty."

My sensor has two wires blue and ground. there is no continuity between the two wires. The weird thing is there is no continuity with the float in either position (up or down). So how does this sensor actually work if nothing changes when the float moves?

 

[allen russell]

hi ni just rebuilt my engine because it had the same problem could not stop the oil sensor from beeping what i found was the plastic gear that drives the oil pump shat was was turning and looked at it with a flashlight looked great but looking with a bore scope turning the engine it was melted now it was turning but was not turning at the right speeds because of damage! when i tore it down to rebuild it found strans of the gear had come apart ! replaced the gear after putting new pistions in and took it to teh lake today and wow it screams !

 

[gohawks688]

hi ni just rebuilt my engine because it had the same problem could not stop the oil sensor from beeping what i found was the plastic gear that drives the oil pump shat was was turning and looked at it with a flashlight looked great but looking with a bore scope turning the engine it was melted now it was turning but was not turning at the right speeds because of damage! when i tore it down to rebuild it found strans of the gear had come apart ! replaced the gear after putting new pistions in and took it to teh lake today and wow it screams !

Wow that's not encouraging. I tested and oil is pumping. However I do not know if it the right amount.
I switched the ignition sense wire to a different coil pack and the beeping went away. That's true of both the old and new alarm module

 

[Faztbullet]

See post #6....