89 Mariner 115 steady alarm question...

docs89gta

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I have read a lot about what to check on this issue. I thought i remembered seeing one post with some good answers after troubleshooting was done, but now can't find it.

I've done some troubleshooting and found that with the key on, engine off, i get the steady alarm. When i disconnect either wire from the oil tank, the alarm goes away. If i disconnect the one going to the temp side, it stays on. Would this signify the oil sensor/float is bad, or something else?

I've seen some talk about a module, but i haven't been able to find a parts listing for it, if that is the problem. For reference the serial is OG677479. I've got both a service manual and a Clymer manual. So far, neither have really helped me on this unless i'm not looking in the right place. I am a noob to the outboard world, but not mechanics.

Thanks for any advice and help anyone can give. Would love to get on the water for the 4th without an alarm going off. :D
 

Jlawsen

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Re: 89 Mariner 115 steady alarm question...

Change the oil sensor. Your test is accurate.
 

docs89gta

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Re: 89 Mariner 115 steady alarm question...

Awesome. Learning things as i go and glad to hear i read and followed correctly. lol.

Thanks for the quick reply. :D
 

docs89gta

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Re: 89 Mariner 115 steady alarm question...

I doubt this would make a difference, but i just noticed i was a little dyslexic :facepalm: and put 89, it's actually a 98 Mariner 115. Just to be on the safe side, is the info still correct? I feel it is, just want to make sure.
 

docs89gta

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Re: 89 Mariner 115 steady alarm question...

Just got off the phone checking to see if the local marine shop has a sensor in stock. He said he believes i will find that i need to replace the actual tank due to a magnet in the tank being the actual problem. I can take the $20 gamble of trying the sensor and then having to order the tank. I just want to ask which would be the most possible problem, if there is one. lol. If i can save on one, it would be nice. $20 for the sensor, $95 for tank local or $70 online. Is it just a gamble either way i go?
 

PuddleJumper

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Re: 89 Mariner 115 steady alarm question...

I would strongly suggest you obtain a manual. It has step by step troubleshooting tests to isolate problem you describe. A steady horn (not beep beep beep) indicates temp issue, not oil. If you don't troubleshoot some more you may be throwing expensive parts in it you don't need. IMHO
 

Texasmark

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Re: 89 Mariner 115 steady alarm question...

I would strongly suggest you obtain a manual. It has step by step troubleshooting tests to isolate problem you describe. A steady horn (not beep beep beep) indicates temp issue, not oil. If you don't troubleshoot some more you may be throwing expensive parts in it you don't need. IMHO

Totally agree. The magnet falling off happens, but the alarm is oil, not the steady temp. The oil warning module is what modulates the signal. Both sensors are merely single pole single throw switches. They are either open or closed and don't jump back and forth beep, beep, beep. It takes electronics to sense the oil fail line and generate a beeping signal to distinguish oil from over temp.

I'd say that you need to spend your money on an oil warning module. To find it the input wire colors should be:Lt blue for the wires from the oil switch, purple for power, black for ground, and tan/blue for the signal that goes to the remote control and causes the alarm to sound.

HTH,
Mark
 

The_Kid

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Re: 89 Mariner 115 steady alarm question...

Per the Mercury service manual to test the oil level switch. Connect a meter on Ohm's setting between the 2 Lt blue wires coming out of the oil tank. When the tank is half full or better the reading should be open. If there is continuity then most likely the magnet has come loose and dropped to the bottom closing the reed switch which triggers the alarm. It's probably time to get a new oil tank.

According to my 95 115 Mariner operating manual the alarm will sound a continuous beep for either low oil or over temp.
 

docs89gta

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Re: 89 Mariner 115 steady alarm question...

I have 2 manuals, a Clymer which i hardly look at and an actual service manual. I will do the Ohms test on it. The alarm sounds without the engine running, that is why i don't think it's the overheat side. I will check the Ohm reading and see what it says.

Is the magnet visible to see if it has come loose? I'm assuming it would be if it comes loose and falls to the bottom of the tank. I'd have to remove the oil anyway and if that's an easy look and see, that would be great.
 

The_Kid

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Re: 89 Mariner 115 steady alarm question...

The float and magnet ride on a tube in the tank with the switch in the bottom of the tube. With the oil out they will both be at the bottom, but you should be able turn the tank on its side and use something to move the float toward the top and should be able to see the magnet if it's loose. It's doughnut shaped with a smaller diameter than the float.

If you can slide both the float and magnet away from the reed switch and test with the meter again it should read open. If it still shows continuity then the reed switch is bad. Although with 40+ years in the electronics field, I've only seen three bad ones and that was because the glass case cracked.
 

docs89gta

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Re: 89 Mariner 115 steady alarm question...

Just went out and tested the 2 lt blue wires going to the oil sensor and i am getting a reading of .000. Tank is still full currently and mounted.
 

bqtoot

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Re: 89 Mariner 115 steady alarm question...

docs:
I have the exact same problem on the almost exact same motor (94 Merc 115hp). Did a lot of reading and know it's the oil sensor. I did the ohms test and got the same reading, 000. I would have thought that if the sensor was bad, I would get something other than 000. I still ordered the sensor. In the meantime, I drained the tank, looked down in there but couldn't make heads or tails on what it "supposed to" look like. According to all I have read, when you disconnect the 2 blue wires under the tank and the beep beep beep stops....it's the sensor. If the new sensor doesn't fix it, I/we may be looking at a new tank...argh!
 

bqtoot

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Re: 89 Mariner 115 steady alarm question...

docs:
update- got the new sensor and installed it. Did not solve problem, still beep, beep, beep with key on engine off. This proves what we suspected, if we both got 000 on the ohms check of the sensor, then the sensor was good. I emptied the tank of oil and looked down in there. Finally made sense of the float on bottom of tank. Made a wire "tool" to stick down in the tank to pull the float up and down. Did not solve the beeps either. Results....oil warning module bad. Go figure. Everything you read says that if you disconnect the 2 blue wires going to the tank and the beeps stop, it's the sensor. As I've found...not necessarrily so.
 

Texasmark

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Re: 89 Mariner 115 steady alarm question...

Per the Mercury service manual to test the oil level switch. Connect a meter on Ohm's setting between the 2 Lt blue wires coming out of the oil tank. When the tank is half full or better the reading should be open. If there is continuity then most likely the magnet has come loose and dropped to the bottom closing the reed switch which triggers the alarm. It's probably time to get a new oil tank.

According to my 95 115 Mariner operating manual the alarm will sound a continuous beep for either low oil or over temp.

Interesting. I have a 90 triple and the manual also covers 4 cyl engines. I did notice in some of the wiring harnesses (which I did look into before I answered the thread) that a warning module was not part of the harness. Soooooooooo I guess if you have a harness without one you get the same tone for either whereas if you have the module you can tell the difference.

From a consumer standpoint, this purely sucks!!!! Some of these OEM designers have their heads in the sand.....so let's see, I'm out in the middle of lake x, I get a solid alarm, Hmmmm do I have a warning module or not....if not, is this solid alarm oil or temp......Hmmmmmm......guess I have to whip out my maintenance manual....Oh, that's back in the shop on my work bench.....now what? (my opinion of course).

Sarcastic........of course. Meant to be? Of course! (Oh, it's 10 am and I just had breakfast!!!!)

Mark
 

docs89gta

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Re: 89 Mariner 115 steady alarm question...

docs:
update- got the new sensor and installed it. Did not solve problem, still beep, beep, beep with key on engine off. This proves what we suspected, if we both got 000 on the ohms check of the sensor, then the sensor was good. I emptied the tank of oil and looked down in there. Finally made sense of the float on bottom of tank. Made a wire "tool" to stick down in the tank to pull the float up and down. Did not solve the beeps either. Results....oil warning module bad. Go figure. Everything you read says that if you disconnect the 2 blue wires going to the tank and the beeps stop, it's the sensor. As I've found...not necessarrily so.

Uh oh. lol. Maybe i should have come back in and checked this sooner. lol. I went ahead and broke down and ordered a tank. What i've read is that there is a magnet in the tank and falls down to the bottom of the tank and that is what causes the short basically. I guess i will find out later this week when the tank shows up. Hopefully it fixes my problem, but i will post either way if it's fixed or not.

Now i have to figure out the idle issue. Rebuilt all 4 carbs, got it running good, but at idle it still has some issues. When i ordered the oil tank, i also ordered a diaphragm kit for the fuel pump. I hope that is the issue. The gas was old, very old that i pulled out of the tank. I guess we'll see if that fixes that issue.
 

mariner115_93

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Re: 89 Mariner 115 steady alarm question...

I had the same problem on July 4th. I did find disconnecting the 2 lite-blue wires stop the beeping alarm so I'm anxious to hear how you make out with installing a new oil container.
 

docs89gta

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Re: 89 Mariner 115 steady alarm question...

I had the same problem on July 4th. I did find disconnecting the 2 lite-blue wires stop the beeping alarm so I'm anxious to hear how you make out with installing a new oil container.

Just got the tank in today. It may be tomorrow morning before i get a chance to get it in, but i may be able to squeeze it in this evening. As soon as i get it in and everything connected, i'll post the results. Luckily if i can get it done before 1pm tomorrow, if this doesn't fix it, i can get the sensor itself locally. I'll post up as soon as i get it together though.
 

docs89gta

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Re: 89 Mariner 115 steady alarm question...

Well, i did get home in time to have some daylight left to get the tank in. I'm happy to say that the alarm is now gone. So, it seems it was the tank itself. I can see the float where the sensor goes at, but can't see a magnet. Nothing was loose in the tank itself. So not real sure what the problem was exactly. All i know is that i have all connections together and no more alarm. :D
 

mariner115_93

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Re: 89 Mariner 115 steady alarm question...

Well, i did get home in time to have some daylight left to get the tank in. I'm happy to say that the alarm is now gone. So, it seems it was the tank itself. I can see the float where the sensor goes at, but can't see a magnet. Nothing was loose in the tank itself. So not real sure what the problem was exactly. All i know is that i have all connections together and no more alarm. :D

Thanks for the update.... How difficult was it to replace the tank. Did you get everything you needed to replace tank or would I need anything else to replace the tank.
 

docs89gta

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Re: 89 Mariner 115 steady alarm question...

Thanks for the update.... How difficult was it to replace the tank. Did you get everything you needed to replace tank or would I need anything else to replace the tank.

I ordered from ********** and got the tank and a new cap. I didn't think the cap came with it, but it did. That is all you need. Just move over the rubber grommet and metal sleeve for the bottom mount on the tank and the rubber grommet at the top around the neck for the upper mount. It wasn't too bad to swap over. Hardest part was getting the oil out of the tank. lol. I'm not sure if you read some of my earlier posts, but i screwed up on the title of this post. I actually have a 98, not an 89 motor. Not sure what years are the same and what's changed. But, shouldn't be too bad for you since i've a definite novice to outboards. lol Hope this helps you... keep us updated. Or at least me, i'd like to know if it's the same results.
 
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