Beeping without key fob on

[RTO]

After sitting in my driveway for a several months my 2005 Seadoo GTX suddenly started beeping as though the key fob was on (it wasn’t).
Neighbors described it but thinking it was an alarm in my garage. It all happened while I was out of town so by the time I got to it the battery was dead. When I began charging it back up the ignition beeping resumed.
I disconnected the battery terminal and gave it a full charge. When I reconnected the terminal of course it resumed again but I also tried to start it but it also would not fire up.
Tried multiple times and finally gave up and disconnected it again and went to grab a beer...
Anybody heard of an issue like this before and/or got an idea where to start troubleshooting it
???

 

[Mekanix]

What did it do when you tried to start it with the key on ?

As in turn over or nothing different except beep.

They disconnecting the post and then reconnect the battery.

Also check the mpem connectors and ecu connectors for corrosion.

 

[RTO]

If I try to start it with the key on it cranks but didn't want to fire up (although it has been sitting now for a pretty long time so maybe there's a fuel issue too).

The battery is disconnected most of the time (except while troubleshooting) because if it is left connected it repeatedly beeps four times until the battery dies.

Will try to check out the MPEM and ECU connectors....thanks

I was looking for a procedure to diagnose the DESS post. I checked for a short on it with a MultiMeter by checking for continuity between the tip and the side contact but it didn't show any continuity..
Not sure if that is an accurate way or not- anyone know if there is a better test other than just buying one and trying it???

 

[Mekanix]

Yes you have 3 wires. White is usually the tip. And black yellow the ring, and when you put a magnet on the front or key you will get a connection between blackyellow and rhe other black wire.

Im thinking yours is always shorted. So computer thinks key is always on.

Disconnect the post. Connect the battery. Does it beep or doesthe problem go away?