1999 Mercury 150 2 Stroke Blue Water Series Oil Alarm Question

[cvflyer]

Took the boat out last week to run as it had been over a month. Ran about 20 miles at various power settings and with several starts and shut downs. Everything seemed to be working great. I get back to the boat ramp, get the boat up on the trailer and hop out to secure the winch. I usually leave it in gear at a medium throttle setting with it trimmed to the top of cowling horizontal to the water line while I do this to hold the bow against the front of the trailer. As I am hopping back into the boat the pulsing oil alarm goes off. I immediately shut down, pull it out of the water and inspect oil levels in the reservoir, engine mounted tank, and oil lines. Everything looked good. Back the trailer back down, started up and immediate warning horn again.

The boat ramp was the steepest I have used with this boat. Is it possible that the angle of the boat on the trailer would somehow result in this alarm going off?

By the way, I'm new to iBoats! Hope I can share some experiences I have had (mostly things not to do) with boats.

 

[alldodge]

Took the boat out last week to run as it had been over a month. Ran about 20 miles at various power settings and with several starts and shut downs. Everything seemed to be working great. I get back to the boat ramp, get the boat up on the trailer and hop out to secure the winch. I usually leave it in gear at a medium throttle setting with it trimmed to the top of cowling horizontal to the water line while I do this to hold the bow against the front of the trailer. As I am hopping back into the boat the pulsing oil alarm goes off. I immediately shut down, pull it out of the water and inspect oil levels in the reservoir, engine mounted tank, and oil lines. Everything looked good. Back the trailer back down, started up and immediate warning horn again.

The boat ramp was the steepest I have used with this boat. Is it possible that the angle of the boat on the trailer would somehow result in this alarm going off?

By the way, I'm new to iBoats! Hope I can share some experiences I have had (mostly things not to do) with boats.

:welcome: to iboats

Appears this has been a big issue with a lot of folks with the same type engine. It's either the pump, float switch or the horn module, and in most cases it's the module. The issue has gotten so bad that many have just cut the wire going to the horn and others cut the wire and start premixing oil and gas. If your seeing blue smoke then your still burning oil

http://continuouswave.com/ubb/Forum3/HTML/010414.html
http://continuouswave.com/ubb/Forum3/HTML/009179.html

 

[achris]

The alarm on those engines is triggered by the alarm module which monitors a few different events. Basically there is a sensor on the oil pump drive shaft, and a pulse wire coming from one of the switchboxes. The alarm module wants to see the shaft signal and the ignition signal in sync. That's how it can tell the shaft is turning when the engine is running, and it's turning at the right speed. What can cause a 'false' alarm is a faulty module, a failed shaft sensor or a failed switchbox. Or a broken wire in one of these circuits. A genuine alarm would be when the shaft or the drive gear for the shaft fails...

HTH,

Chris.......

 

[cvflyer]

The alarm on those engines is triggered by the alarm module which monitors a few different events. Basically there is a sensor on the oil pump drive shaft, and a pulse wire coming from one of the switchboxes. The alarm module wants to see the shaft signal and the ignition signal in sync. That's how it can tell the shaft is turning when the engine is running, and it's turning at the right speed. What can cause a 'false' alarm is a faulty module, a failed shaft sensor or a failed switchbox. Or a broken wire in one of these circuits. A genuine alarm would be when the shaft or the drive gear for the shaft fails...

HTH,

Chris.......

Thanks. I was hoping that maybe it was related to the angle of the boat on the trailer but it sounds like it probably wasn't. It is just a strange coincidence that it would alarm after running for several hours just fine.

One of the first tests I did out of the Clymer maintenance manual I have was to test continuity on the engine mounted tank. I'm recalling this from memory, but I checked that the tank was full and then checked continuity at a bullet connector which there was none. According to the maintenance manual this was a good check. However, I also removed the cap which has a float sensor and allowed the float to slide all the way down (which should send a low oil signal if I'm thinking about this correct). I tested the continuity again and still had none. It seems to me that I should have had continuity at that point. Everything was turned off during the test. Am I thinking about this correct?

 

[achris]

Easiest way to check the engine mounted oil tank sensor (the bottle cap) is to just disconnect one of the wires going to it. If the alarm stops, you found the problem, if it doesn't, keep looking....

BTW, toss the clymer... They are as incorrect as they are misleading...

Chris.......

 

[cvflyer]

BTW, toss the clymer... They are as incorrect as they are misleading...

Chris.......

Funny you say that. I stripped one (maybe two) holes for the thermostat bolts because they showed the rubber seal wrong. Also, installed the fuel filter in reverse based on a bad diagram they had. I have been running the boat for three months with the fuel filter in reverse. I figured that one out while troubleshooting the oil alarm problem. I'm not the most mechanically inclined boat owner so I rely pretty heavily on the manual. Is Seloc any better or should I just try to find one from Mercury?

 

[achris]

..... Is Seloc any better or should I just try to find one from Mercury?

No... Yes...

What's your engines' serial number?

 

[Dukedog]

try here.......

http://boatinfo.no/lib/mercury/manuals/135-150-175-200.html#/0

 

[cvflyer]

No... Yes...

What's your engines' serial number?

0G912981

 

[cvflyer]

I have been going through some service manuals online and am a bit confused as to which applies to my engine. According to the Mercury parts catalogue I should use 90-824052R2 from 1997. However, when I browse other service manuals, the title pages show that some newer service manuals (i.e. 90-824052R3 from 2002) cover my model and s/n engine. Should I stick with the older one per Merc. parts catalogue or go with one of the newer manuals?

 

[achris]

90-824052R3 is the updated version of 90-824052R2.... Both cover your engine, but R3 will have the latest information...

 

[cvflyer]

Another update and a couple more questions. I pulled the bullet connectors for the white wire from the alarm module to the motion sensor. I tested voltage coming from alarm module in the white wire with the key turned to the on position. It read 7.2 volts. I then put the multimeter to the battery and read 12.4 volts just to verify battery voltage was good.

This seems to me that the alarm module is bad. However, I do not have a DVA adapter to test peak voltage from the ignition coil. Is it possible that the problem could be in the ignition coil even when the engine is off and key is in the on position? Could this lead to the alarm module not receiving the correct voltage with the motor off? Is there any other way to check the ignitions system without the DVA adapter.

I am going to run the motor tomorrow on premixed fuel and verify the pump is actually working. I am also going to check the output of the motion sensor per the service manual. Any other recommendations?

 

[achris]

If you have the alarm without the engine running... Then lift the wire off the switchbox that goes to the alarm module. It should be green. If you still have the alarm, 99% it's the 'lubalert' module....

Chris......

 

[cvflyer]

If you have the alarm without the engine running... Then lift the wire off the switchbox that goes to the alarm module. It should be green. If you still have the alarm, 99% it's the 'lubalert' module....

Chris......

The alarm is only sounding when the engine is cranking or running. It will start sounding as I start cranking the engine. It does not come on with the key in the on position. I did some more troubleshooting last night before I saw any more forum replies and here is what I have now.

1. Confirmed it is not the reservoir float sensor by continuity test.
2. Confirmed that oil pump is pumping. Disconnected oil line from injection pump to fuel line T connector and got 3 drops of oil during a 5 second cranking cycle. I couldn't get the motor to run on 50:1 mixture separate tank to test over a longer period (probably due to my incompetence). Motor is also blowing out blue smoke on start indicating it is burning oil.
3. Reconnected oil line and disconnected all three bullet connectors coming out of the alarm module. Cranked for about 5 seconds and oil alarm came back on during the cranking cycle. I did encounter a strange event after the first crank attempt with all the bullet connectors disconnected. On the second attempt there was no electrical power to the entire motor and boat (no tilt, no pre-start beeps, no lights, no cranking). I waited about 5 minutes and everything came back and motor turned over fine.
4. Researched the "beep" sequence that should be made when turning the key to on. According to some other forum posts it should "dah, dit, dit" or long, short, short. I am only getting a "dah, dit" or long, short when I turn the key.
5. Tested the output voltage on the white wire form the alarm module and it was 10.8V with battery voltage reading 12.4 V. Voltage coming from switch box before the alarm module was 11.6 V

I have also noticed some lower voltage readings (7-8 range) at all the test points. I disconnected and reconnected the main wiring harness connector which corrected the low voltage issue throughout the boat. However, I do not think this is the reason for the low oil alarm.

​At this point, I am leaning towards the alarm module. Any recommendations?

 

[cvflyer]

Replaced the alarm module and it worked. Thanks for the references and pointers.