It rained like crazy here yesterday and then my 2002 Discovery wouldn't start. There is now a rear speaker that has a constant bumping sound that is quite faint. I assume something got wet and it set off the speaker draining the battery.

Can I just disconnect the speaker and try to jump it?

Any other suggestions?

 

Speakers aren't connected to battery power, they are connected to the head unit and/or amp.

Sounds like you might want to start by charging your battery, and then using a multimeter to check the load on the battery as you pull fuses. When you find one that significantly drops the load on the battery it's likely the culprit.

 

There is sound/noise coming from them. First it was the rear speaker, which I disconnected. After disconnecting it the right rear side speaker starting making the same sound at a slightly higher pitch (I'm assuming because they are the highs). The sound is on even when the car is off.

Also, I jumped the battery and the car started fine. I've driven it around and it has started fine 8 times since the battery seemed like it died.

 

Totally not related.

 

It's true!
Last week the rear speakers would screech like crazy with the radio off. Running the radio would only attenuate the noise but it would still buzz. Did that 3 times the same day. Never happened again ???

This truck is possessed,

 

How is a head unit or amplifier staying powered up when the truck is off not related to a battery drain issue?

 

is it humming while the car is running? or off?
if it is humming while it is running you probably have a ground issue, or some kind of voltage bleed over from your charging system.
check all your connections for corrosion and tightness.

 

My thoughts exactly. I know you can get noise from the system if there's water in the line but wouldn't that still drain the battery as long as there is any kind of sound output?

 

Check all connections? Where do I start? I checked the battery and connections around the speakers and everything seemed fine so far.

 

Remove your serpentine belt and then run the engine and see if the noise is still there.
If not then its RFI (radio frequency interference) from the alternator, either because it is going bad (that would explain the dead battery) or a loose wire on the alternator.

If it IS still there without the belt on the engine then it could be a bad spark plug wire or two.

But because of the rain, the type of noise and the dead battery I am leaning towards a alternator issue.