Diagnozing my warning buzzer

[hundee r1]

Just crossing my T's since rebuilding my motor so thought Id test my buzzer.

Earthed it out:

Ignition on, expecting a warning, got nothing.

Head under the dash looking for a buzzer and seen I didn't have one. But I seen a brown wire with a purple stripe which came out from the controls along with my other dash wires.


(yes the wiring is messy and a rewire is on the bucker list)


Thinking this was meant to go to a buzzer, I used a test light to test this wire, surprised that when I earthed it out I have a warning buzzer sound inside the control box!!

Confused and wanting to make sure I have a working system any body able to tell me how to work it out?

The wiring loom from the motor coming into the controls is all in a sheath, but coming out of the controls and amongst the rest of the loom is this brown/purple stripe wire. Not sure what this loose brown wire is meant to go to



Also worth mentioning is that the buzzer would sound when Id earth this wire regardless of what I did with the sender at the motor.

Please help?

 

[jerryjerry05]

Re: Diagnozing my warning buzzer

That one is for the overheat.
Follow the sender/sensor and see where it hooks up.Looks like the lead got unhooked?
Depending on the boat manufacturer the buzzer was under the dash or in the shifter.
If you ground out the t/b lead and the buzzer sounds? GOOD means it's working.
Test the sender, should be no resistance when it's cold. Will close above 160.

 

[hundee r1]

Re: Diagnozing my warning buzzer

Hmm, realize its the overheat sensor. It's on a tan/purple wire. Disappears into the main loom at the motor. Into the controls its not visible cos the loom is in the black sealed conduit. It re-appears in the loom coming out of the controls to the under dash. This same tan/purple wire is left under the dash un connected. It's earthing this end under the dash that sounds the buzzer inside the controls.
No idea what the plain tan wire out of the controls does.
Earthing the sensor at the motor makes no difference to what happens when earthing the wire under the dash.

 

[Frank Acampora]

Re: Diagnozing my warning buzzer

You can NOT simply ground the outside case: Inside is a bimetal switch which closes only when a set temperature is reached. Now, ground the case with a wire and heat it with a match or cigarette lighter and it should activate the buzzer as it heats somewhere past 200 degrees.

Oh, BTW: You have Mercury controls. The warning buzzer is inside the control box next to the ignition switch. Your Mercury wiring is probably standard and may have an extra unused wire which would activate the warning buzzer on Mercury engines with oil injection, indicating no injection or low oil in the tank.

 

[hundee r1]

Re: Diagnozing my warning buzzer

That makes a lot of sense Frank, il be sure to give it a shot after work 2morro and report back.
I owe u and jerry many a beer if ever I'm my neighbor hood!!

 

[hundee r1]

Re: Diagnozing my warning buzzer

10secs or so with a lighter and I had a screeching buzzer!!!

Once again guys, epic help, THANX!!!

Will add a tell tale or pressure gauge anyway, but its nice to know the buzzer works!!