Another warning alarm question?

[buster5966]

I have a 87 evinrude 110 VRO. Im pretty sure the buzzer is bad. When I disconnect the two leads, (one has two puple wires and the other is a single tan wire), and connect a vom I read 11.8volts across the leads with the key in the on position. I would think I shouldn't read any voltage at this point. When I ground the thermo wires it jumps to 12.8v it also jumps to 12.8 when I activate the cil tank alarm. Why am I reading 11.8v before any alarm is activated. By the way I did hook up a piezo from R.S. and because of the constant 11.8 it sounds constantly. It does get a little louder when I ground the thermo wire because of the 12.8v rise.

 

[Solittle]

Re: Another warning alarm question?

YOur post is a bit confusing but if the switch is on and you ground the brown or tan wire the horn should sound loudly.

 

[buster5966]

Re: Another warning alarm question?

Let me try to clarify.. If the buzzer itself was not bad I believe it would sound constantly. There are 11.8 volts at all times across the two leads that attach to the buzzer. One is tan and the other is purple.

 

[buster5966]

Re: Another warning alarm question?

Does anyone know what could be causing the 11.8 volts to be present at all times?

 

[Dhadley]

Re: Another warning alarm question?

There will be 12 volts there if the key is on. The sender in the head completes the circuit to ground if the motor gets hot causing the horn to sound.<br /><br />Its oppsite of --say a stern light -- where the light is always grounded and you add 12 volts to turn it on. The horn is hot with the key on (purple wire) and if the circuit is completed thru the sender (brown / tan) to ground, you have noise. <br /><br />If the horn does not have the self test mode (should be another wire) I'd suggest getting a new one that does.

 

[buster5966]

Re: Another warning alarm question?

Thanks Dhadley, With the two head sensors disconnected I still have 12 volts across the two alarm leads. I understand the key supplies power to the purple wires and the tan provides the ground. With the head sensors disconnected, what else would cause a ground completing the circuit.

 

[buster5966]

Re: Another warning alarm question?

P.S. I have also disconnected the VRO sensor plug.

 

[Joe Reeves]

Re: Another warning alarm question?

Buster.... I believe what you're saying is that when the horn is wired as it should be, and you turn the key to the ON position, the horn sounds constantly.... and from your descripion of the horn, it is a two (2) wire horn which simply has two push on type terminals. One for the purple wire and one for the tan wire.... and there is no internally conected black ground wire.<br /><br />If so leave the volt meter hooked up to the disconnected purple/tan wires whereas you obtain that 11.8 reading. Then, one by one, disconnect the connection to the oil tank, then the VRO, then the heat sending unit(s) at the cylinder head(s).<br /><br />When the horn stops sounding, you will have found the faulty sensor.<br /><br />I've never encountered a faulty heat sensor acting like that, but you could very well be obtaining that 11.8v reading thru a faulty electronic circuit of the vro or oil tank.<br /><br />If with everything disconnected, the voltage is still present, it's possible that a break in the wiring exists which is water logged, something of that nature. Let us know what you find.

 

[buster5966]

Re: Another warning alarm question?

Thanks Joe,<br />On your advice I disconnected The VRO, The Oil tank and the 2 sensors. With all 4 disconnected the voltage was gone. Then I re-connected each item one by one. <br />1. VRO-still no voltage<br />2. Oil tank- as soon as I connected I read 12 volts<br />You would think it was the oil tank sensor but when I re-connected the one head sensor 12 volts. And with the other head sensor only connected I read 7 volts. Looks to me I have a bad oil tank sensor and 2 bad head sensors...what do you think?