alarm continuesly

Hey first post
95 evinrude 115
alarm sounds consistanly at times. sometimes when boat has not started yet for the day.
changed water pump and thermostats,
after done before starting alarm sounded, unplugged both temp sensors in heads
still goes off, unplug vro, still sounds unplug oil tank and sound quits,
have factory service manual but says nothing of spec for system, has a wiring diagram, tan wire tied to two temp sensors in head, vdo and oil level, i am master gm tech master ase tech and can not believe factory book not more specific, for me to understand is poo
so the same circuit conected in series does three different things, so for this to happen has to be looking a resistance to ground? i assume, but how does it make it beep every 40 seconds or 1/2 sec on and 1/2 sec off.
alarm has three wires. purple, black and tan. purple has 12volts and black has ground. tan is grounded when horn sounds continusly

any help would be greatly appreciated.

Re: alarm continuesly

Hi James, your problem is in your oil tank sender. There is no test for the circuit. if your getting a horn and when you unplug the component, it stops, that's generally where the problem exists. you replace the component

Re: alarm continuesly

"........alarm has three wires. purple, black and tan. purple has 12volts and black has ground. tan is grounded when horn sounds continusly"
...

The black lead on the horn is used to give a test beep when the ignition is first turned to run. The rest is gounding the tan wire from the engine.

The test beep is just to let you know that the horn is functioning properly.

Your oil side system has a few years on it; air leaks will cause the oil alarms to go off. The filter in the oil tank can clog and cause problems as well.

The information in the following thread is generally found in Section 2. Fuel System, of your factory service manual.

http://www.maxrules.com/graphics/vropics/VROwarning.gif

Re: alarm continuesly

Those warning horns can develop a internal flaw, to test........

When the horn is sounding as you describe, remove the TAN wire from the horn. If the sound continues, the horn is faulty, in which case replace it.

Re: alarm continuesly

Either the float switch in the oil tank has died or the low oil level contact on that switch has shifted, either way you will need to pull the pickup out of the oil tank to check.

The new pickup assy comes with new hose and wire.

Re: alarm continuesly

under stand but still unsure how two wire sensor in tank can make alarm beep every 40 seconds. if the sensor in the tank is a on-off swich how does it come on and off every 40 seconds, how does the vro make it sound 1/2 second on off. i understand how every thing is wired just not how it works.
so what i am wanting to understand is how does the alarm wired in series distinguish between witch sensor. i know the temp sensors in head are open closed sensors. and it makes sense why the alarm sounds continusly. but looses me on how it comes on and off in a 40 second or 1/2 second interval
depending on what, like the book states.

Re: alarm continuesly

James...... It's not necessary to uunderstand how the electronic circuitry works, it is important to know that this is the way it works. And when it doesn't work this way, something is amiss.

The every other second (VRO), 20 second (older oil tanks), 40 second (newer oil tanks)..... it is just the way the circuitry is designed.

Take the signal light system in your automobile (the flasher), a circucit that is designed to go on and off. Who cares how it works, it's just impotant that it does.

Now, did you have a chance to remove the TAN wire from the horn when it's sounding off, and if so, what was the result?

Re: alarm continuesly

yes when pull tan wire off alarm it quits. going out rite now to pull pick up out of tank and "see how it works" let you know. thanks