Alarm won't shut off

[Storkboy]

94 mercury 60hp 2 cycle has been running great. Put new thermostat on motor 2 weeks ago. Went to crank her up this past weekend but the alarm which usually sounds when the key is turned( but shuts off) now just keeps sounding continually. Any ideas

 

[Iceman66]

How is the sound?Is it a long " beeeeeeeeeeeeeep or beep-beep-beep-beep-beep

Do you have an oil warning modul on your engine?
These units has a bad habit to corrode inside.Disconnect it if you have one and see
if alarm shuts off.(You will not have the "beeeeep.beep-beep"sound while turning the key while modul is disconnected.

Could also be a bad temp sensor.
Disconnect the wire from temp sensor.If alarm shuts off, you sensor probably is bad.
If still sounds; check your key switch and remote control harness and connections.

 

[Storkboy]

It is a continuous beep. This is my first Mercury and I'm learning my way around it. I just ordered a temp sensor but I will try and disconnect the temp switch and see if that works. I'm not sure where it is but a friend told me to try a new temp sensor and then a new water pump.

 

[Storkboy]

Ok, changed out the temp sensor and still have the beeeeeep! I'm not sure if I have an oil warning modulator or not. I will try to find it. Need a manual cause I don't know where to look for that one!!!!

 

[Iceman66]

Just so we are talking same "language" here: The alarm sounds continually when turning the ignition key?
Or after you have started the engine?

On 60 merc the oil warning module usually is mounted low on starboard side of engine block.
Getting a manual will help you a lot with ALL troubleshooting.

 

[scootchu]

Having just went through something similar, only with a oil beep-beep alarm when the engine was off, but the key was on, I found it to be a bad alarm module. It could be that, but it's a costly gamble to replace it. How many temp senders? My 150 has two, one for the alarm and one for the temp gauge. I would say you either have a bad module or a sender wire grounded. Take a multimeter and test for continuity to ground from the sender wire in the harness to the engine block. I believe it should be tan. There's no way a temp alarm should sound with a cold engine.