warning horn sounding off

[imported_Tman]

I'm new to this forum; I have a 1990 mercury 115 and the warning horn has a steady beep when I turn on the switch,I've disc.the temp sensor & the oil sensor and the horn still sounds off!is there anything else I can test to isolate the problem?

 

[Silvertip]

Re: warning horn sounding off

Check the tan wire that was connected to the temp sensor. It might be shorted to ground between the sensor and control box. If not, the horn is bad.

 

[gss036]

Re: warning horn sounding off

Did you check the float inside the onboard tank? Take the cap off, turn it upside down and then reinstall it, tightening just enough to keep it from leaking as they have a tendancy to split at the top of the threads inside the cap if too tight.
You say steady, BEEEEEEEEEEEEEP or Beep-beep-beep?

 

[imported_Tman]

Re: warning horn sounding off

Did you check the float inside the onboard tank? Take the cap off, turn it upside down and then reinstall it, tightening just enough to keep it from leaking as they have a tendancy to split at the top of the threads inside the cap if too tight.
You say steady, BEEEEEEEEEEEEEP or Beep-beep-beep?

 

[imported_Tman]

Re: warning horn sounding off

It has asteady BEEEEEEEP

 

[gss036]

Re: warning horn sounding off

OK! That is an overheat alarm. You have 2 sensors/senders on the engine, one on each head. The one on the port is for a temp guage, the starboard is for overheat, goes off at 243 degrees. Check your grounding wires, they both have to be grounded to work.
The overheat sensor on the starboard head is just a flat button that will pop out and then reset when the head cools down about 20 degrees.

 

[andy6374]

Re: warning horn sounding off

It's the tan/blu wire

 

[imported_Tman]

Re: warning horn sounding off

OK! That is an overheat alarm. You have 2 sensors/senders on the engine, one on each head. The one on the port is for a temp guage, the starboard is for overheat, goes off at 243 degrees. Check your grounding wires, they both have to be grounded to work.
The overheat sensor on the starboard head is just a flat button that will pop out and then reset when the head cools down about 20 degrees.

 

[imported_Tman]

Re: warning horn sounding off

Gary I found the port sensor unable to find the starboard side sensor. Is there any way to test the warning module ?

 

[gss036]

Re: warning horn sounding off

Try disconnecting the wiring harness plug from the engine, it is located on the lower starboard side of the block, tucked into a recess. That will at least let you know if it is something from the engine or the horn itself is bad/shorted. Look close at the connection/pins and clean up any corrision you might find inside and spray it down w/wd-40 or something like that before putting it back together.
Did you remove the sensor? What does it look like? Do you even have a temp gauge on the boat?

 

[barber702]

Re: warning horn sounding off

Try disconnecting the wiring harness plug from the engine, it is located on the lower starboard side of the block, tucked into a recess. That will at least let you know if it is something from the engine or the horn itself is bad/shorted. Look close at the connection/pins and clean up any corrision you might find inside and spray it down w/wd-40 or something like that before putting it back together.
Did you remove the sensor? What does it look like? Do you even have a temp gauge on the boat?

 

[barber702]

Re: warning horn sounding off

Try disconnecting the wiring harness plug from the engine, it is located on the lower starboard side of the block, tucked into a recess. That will at least let you know if it is something from the engine or the horn itself is bad/shorted. Look close at the connection/pins and clean up any corrision you might find inside and spray it down w/wd-40 or something like that before putting it back together.
Did you remove the sensor? What does it look like? Do you even have a temp gauge on the boat?

Gary,
I'm new here also and have a simular problem only my merc 200hp has a "beep beep beep" and I've been trying to start a thread on it but it keeps telling me I can't do it so I'll ask the question here and maybe you can help or tell me why it is i can't start my own thread,

I installed an oil sensor to the port side but still get the beep beep beep, the motor runs fine and isn't overheating but it is a little scarey with the beeping going on.

Should I also try unhooking the harness to see if the problem is in the horn??

 

[imported_Tman]

Re: warning horn sounding off

I'll try that will keep you posted

 

[barber702]

Re: warning horn sounding off

I finally got my own thread titled "merc 200hp motor going Beep beep beep"

 

[gss036]

Re: warning horn sounding off

We are talking 2 different type of problems here. One is oil, the other is temperature.

 

[imported_Tman]

Re: warning horn sounding off

gary Ive disc the harness next ti the cotrol box and the horn still sounds the harness has 5pin connector did not disc the harness in the callon.Do I need to disc this harness?

 

[delsol]

Re: warning horn sounding off

2 QUESTIONS. i have the solid beeping on my 89 80 hp.
i changed the oil line early this year and let boat sit.the tank got totally empty.so i fill it.

2# the water is spraying like mad from the pee hole, can i still be running hot???
also how do you know if the oil injection is really working??
the beeping is solid. steady. last year i had some beeping and i cleaned the battery cables and it went away. any help would be great.
bob/philly

 

[imported_Tman]

Re: warning horn sounding off

Gary I disc the wiring harness in the engine compartment Im afraid its the warning modjule:'(

 

[delsol]

Re: warning horn sounding off

8) ALL FIXED WITH NEW THEMOSTAT. water pump. popet valve. i thought it was peeing good before for 2 years was i wrong it really pees now
fixed
bob

 

[delsol]

Re: warning horn sounding off

2 QUESTIONS. i have the solid beeping on my 89 80 hp.
i changed the oil line early this year and let boat sit.the tank got totally empty.so i fill it.

2# the water is spraying like mad from the pee hole, can i still be running hot???
also how do you know if the oil injection is really working??
the beeping is solid. steady. last year i had some beeping and i cleaned the battery cables and it went away. any help would be great.
bob/philly