88 Evinrude alarm question

[nkyhusker]

I borrowed my father's fishing boat this weekend and caused the alarm to sound continuously by disconnecting the battery while the engine was running. I have searched the posts here to understand why this occurred and have not found a complete answer.

In several posts, it is stated that the battery should never be disconnected while the engine is running but does not explain why this is so. Please explain to me what occurs or could potentially occur when this is done.

Secondly, now that the alarm is sounding continuously under all conditions, how do I make it stop? Does it have to be reset once it starts? Did the break in connections fry another device?

 

[nkyhusker]

Re: 88 Evinrude alarm question

I think that this is a basic question but one that I don't know the answer. Please give me a hand by posting a response or sending a PM to me.

 

[WillyBWright]

Re: 88 Evinrude alarm question

It's going to need a new rectifier and a new alarm. By disconnecting the battery while the motor was running, electricity already produced by the alternator needed a place to go and blew one or more diodes in the rectifier to find it. It's usually just the rectifier, but any electronic device is subject to failure by the spike produced and that's what damaged the alarm. Those are designed to sound continuously in event of failure rather than fall silent forever. Now for the silly question...why did you disconnect the battery from the running motor?

 

[Dennisanoka]

Re: 88 Evinrude alarm question

WillyBWright-

Why would it need the alarm replaced too? Is it part of the rectifier?

 

[nkyhusker]

Re: 88 Evinrude alarm question

Thanks for the reply, Willy.

The sequence of events that led to disconnecting the battery went something like this: I was using the engine battery to run lights and the aerator pump to my shad tank. I drained this battery and had to use the trolling motor battery to start the engine. By this time, I had been on the water from 9:30 PM until about 5 AM (awake nearly 24 hours at this point) and wasn't thinking very clearly. The idea that occurred to me was that I could start the motor with the trolling motor battery then switch to the engine battery to recharge it. You know the rest of the story.

 

[WillyBWright]

Re: 88 Evinrude alarm question

The alarm is an electronic device, separate from the rectifier, but part of the motor's extended electrical system. The alarm has a self-test feature and the tone indicates that the alarm has sustained a failure, probably a component of the self-test circuitry. Ironic, the self-test system part of it is what failed necessitating replacement of an otherwise rather simple device that would've probably survived the spike.