Early Warning Detection System Failure.

[Captain Crunch]

Hi,

Has anyone experienced problems with the EWDS failing into alarm?

I had it throw a coil failure last weekend. All my tests proved that the coil was fine and operating properly.

I disconnected the coil sensor wire and the system was still alarming but without the coil light.

All other sensors were operating as they should.

Is there any tests I can do to prove the EWDS unit is failing or operating properly? None of the other sensors were grounded with no other lights on but the alarm still sounding.

Thanks in advance!

CC.

[ndutton]

To test the coil voltage input function connect the purple coil lead from the EWDS to a known good 12V+ source. If it’s functioning properly the trip event will clear. Remember, the EWDS does not monitor coil function but rather sufficient voltage input to the coil.

When you disconnected the coil lead you eliminated the power source to the light display and created a low voltage signal to the EWDS coil input resulting in the no-light audible alarm as you experienced.

[Captain Crunch]

Thanks Neil! I will check it out tonight.

CC.

[Captain Crunch]

Hi Neil,

I was able to clear the alarm. Thanks for the instruction.

I'm not sure what caused the alarm in the first place but in future are we required to reset the coil alarm with a 12V jumper? I do have a resistor in front of my coil and the coil receives 11.4V with the motor running and the alternator putting out. I reset it by jumping from my closest 12V source.

I am assuming that a relay drops out when coil voltage drops below the set parameter(9V?)but should re-latch when it receives above that. Is this correct?

One more thing....where do people usually install the RW flow sensor? It is plastic and we usually dont put plastic below the water line. I was assuming between the through hull and the strainer? Do people extend the RW intake line from the through hull above the waterline install the sensor there and then back to the strainer?



Thanks again for the insight and I love the EWDS addition to my A4.

CC.

[ndutton]

If your resistor ahead of the coil is aggressive** I suspect it dropped the voltage enough to cause a trip event. In your case I recommend connecting the purple EWDS wire ahead of the resistor to avoid a repeat episode. As for the location of the flow sensor, I recommend installing it in the raw water pump discharge line and oriented horizontally. The principle here is to have the pump pushing water through the sensor rather than drawing through it. The horizontal orientation cancels out gravitational influences that could affect the sensor's function.

When I read your opening post I immediately thought we needed to determine whether the voltage sensing circuit failed (thus far they've been remarkably reliable) or was it doing its job and warning of a low voltage condition - - at the point of connection. The 12V+ test you did was in fact just a test, not a reset. There is no reset feature built into the circuit. The trip point is approximately 9V, approximate due to minuscule manufacturing variations in relay coils. FYI, each EWDS is fully tested on all parameters prior to packaging. The voltage sensing circuit is tested with a digital variable voltage apparatus.

**How did you determine the size of your resistor? If you used the resistor calculator we provided in any of several forum threads on the subject you should be in the sweet spot. That is, sized to protect your coil on your particular boat but not overdone. If you used an Indigo resistor, they approach it as one size fits all. If you guessed on your own - - - - well, I can't really help with that.

[Captain Crunch]

Hi Neil,

The resistor I use delivers 11.4V to the coil with the motor running. I use the Pertronix ignitor EI. I can't remember the exact resistance...I do remember sizing it correctly and doing all the appropriate research here on the forum.

The EWDS has been performing great. This is the first time it has given me an error. I think I will go through the primary ignition cct and look for a loose connection. I bet I will find one! Thanks!

[ndutton]

If your alternator output is 14.4 volts (unknown, for example only), your resistor is dropping 3 volts. Reduce the RPM to idle so the alternator drops out and you're on battery voltage only, let's say 12 volts (maybe but also unknown), the resistor drops it 3 volts and all of a sudden your coil input voltage is at the EWDS trip point. This doesn't take into account ignition system voltage drop, poor connections as you mentioned, etc.

[Captain Crunch]

Hi,

It looks like I have a problem with my EWDS. It is still nuisance alarming. If I tap the module the alarm will stop. It was a last ditch effort....just a little tap.

Then maybe it will alarm again in a few minutes or not...very intermittent. It always seems to be the coil alarm. It sounds like there is a little relay in there that is held open, by the coil voltage? I have the sense wire move upstream of my resistor.

Anyways, any more suggestions on trouble shooting?

Thanks in advance.

CC.

[ndutton]

Would you entertain sending it to me for bench testing?

[Captain Crunch]

Hi Neil,

I have sent you my EWDS unit for test as per Don Moyer.

It is coming from Victoria, B.C. so it shouldn't take long.

I wrote a little note on the inside of the shipping label with my number and email address.

Thank Neil. Keep me posted.

CC.

[ndutton]

I'll post when it arrives. Thanks