1988 100 hp mercury, constant beeping at key on

holorinhal

Petty Officer 2nd Class
Joined
May 26, 2009
Messages
119
Ok so with the help of some good people on this forum, I got the year and model figured out and how to hook up 12v power.
Now for the real problem.
About 15- 20 years ago, hell I have lost track, My Dad pulled this motor off of his bass boat, because he thought that it had an oiling problem. He pulled it immediately so I do not think that it was damaged. The motor has sat since then and I have hauled it around every where I have moved. My dad has since passed and I do not remember what he told me was the reason he thought it was an oiling problem.
I took the spark plugs out and turned the motor and it turns freely by hand, by rotating the flywheel.
I made a set of battery cables and put some power to it to see if it would turn over from the key, and it does.

Here is the problem. As soon as the key is turned on, Key on only, a constant, rapid beeping is coming from the control. It is a continuously beeping and not a solid tone and does not stop.
From what I read this is an oil warning alarm. This may be why My Dad thought it had an oiling problem.
I just finished reading in another thread, about the magnet in the oil tank may fall off and cause an alarm. They said to test it by unplugging he wires coming from under the oil tank.
So I went out and turned the key on and the continuous beeping started. There are two white wires coming from the bottom of the oil tank, plugged to two blue wires.
I unplugged one wire and the beeping stopped. Plugged it back in and the beeping started again. I unplugged the second wire and the beeping stopped, plugged it back in and beeping started again.
So does this mean it is a problem with the sensor in the tank, or are there other things to check?
 

holorinhal

Petty Officer 2nd Class
Joined
May 26, 2009
Messages
119
Re: 1988 100 hp mercury, constant beeping at key on

If the magnet has come off the oil float, can the float be replaced or does the whole oil tang have to be replaced?
Is tere any thing else that can cause the constant alarm with only the key on?
 

Fred.Furrer

Recruit
Joined
Aug 27, 2013
Messages
5
Re: 1988 100 hp mercury, constant beeping at key on

Amazingly, I just asked the same questions you did. It looks like no one replied to your questions. You should watch my thread to see if anyone answers it.
 

Iceman66

Petty Officer 2nd Class
Joined
Jun 30, 2008
Messages
199
Re: 1988 100 hp mercury, constant beeping at key on

Usually the low oil warning sound is a beep-beep-beep-beep, the constant beeeeeeeep is for overheating.

When turning the ignition key to on ,you should have a short beeeeeep-beep-beep and then silence.
This confirm that your warning circuit is ok.

My guess is that your oil warning module is defect,but follow all the wires(except black) from module and check that they dont hit ground anywhere .

Disconnect the wire from temp sensor ,see if sound stops.
 
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