Alarm on Merc 80

[kalberg]

Just took my boat down to the lake after 3 weeks sitting in the yard. When I turn the ignition to "run" I het a constant beep alarm. This happens before I even start the motor. Once the motor starts the beep (constant) coninues.<br /><br />We ran the oil injection tank pretty low last time out to the level that it started the beep-beep-beep, got back to the dock without running the tank dry (this motor has the tank mounted on the powergead under the motor cowling.<br /><br />Sounds like a temp sensor?!? Anyone have any ideas?

 

[hondon]

Re: Alarm on Merc 80

Take the engine cover off and look at the rear of the engine.There you will see the spark plugs and the BIG wires that go with them.To the left of those wires ,or somewhere in that area you will see a light brown wire that seems to disappear into a cylindrical looking thing.That is your temp sending wire and you should be able to unplug it very close to where you are.Do that and then start that engine and if the horn goes away you need to replace the temp sender .If not move on to the oil sender in pretty much the same fashion.We'll get to the warning module later.

 

[kalberg]

Re: Alarm on Merc 80

Thanks hondon! I pulled the light brown wire and all is well. Looks like I need a new sending unit.<br /><br />The Clymer manual is crap. Do you have any suggestions on a better service manual for a 89 Merc 80 OB??<br /><br />

Originally posted by hondon:<br /> Take the engine cover off and look at the rear of the engine.There you will see the spark plugs and the BIG wires that go with them.To the left of those wires ,or somewhere in that area you will see a light brown wire that seems to disappear into a cylindrical looking thing.That is your temp sending wire and you should be able to unplug it very close to where you are.Do that and then start that engine and if the horn goes away you need to replace the temp sender .If not move on to the oil sender in pretty much the same fashion.We'll get to the warning module later.

 

[ronmold]

Re: Alarm on Merc 80

Try the Seloc

 

[kalberg]

Re: Alarm on Merc 80

hondon:<br /><br />One more stupid question. i was planning on taking the boat out this weekend before I have the temp sending unit replaced. When I dosconnected that brown wire did I also disconect the oil sending unit too?? I'm sure the motor is not overheating, but I am always paranoid over the oil injection system. Just want to make sure I did not disable that too...<br /><br />Thanks!<br /><br />I'm ordering the Seloc book today...

 

[hondon]

Re: Alarm on Merc 80

You're alright.They are 2 separate sending units.

 

[saumon]

Re: Alarm on Merc 80

(first of all, please excuse my english cause i'm french speaking)<br />just for your information, i think that the temp/overheat sensor is a lot more important.<br /><br />As for the oil warning module, it won't tell you if the oil system isn't working. It's just a low-level warning alarm, so if, by example, the oil line get clogged or the oil pump fail and the motor doesn't get any lubrication, you won't heard any alarm sound if your oil level isn't low but your motor will soonly overheat (and you'll get an alarm IF you had an overheat/temp sender)!<br /><br />Hope it could help.