Hello!
I'm new to the whole Land Rover world, and I looked up on a few different forums about this specific problem I'm having but haven't been able to find anyone else with it. Currently, I have a 2003 LR3, and only the rear speakers are working. What could be a potential reason for this?

Thanks in advance!

 

First things first - 2003?

I assume you confirmed Fader is not set to rear?
After that, check connections at back of stereo, and at each door

Could be anything from loose connections to blown speakers to requiring a new head unit
What have you tested or eliminated?

 

Nope! Not a fader problem - when put up all the way to Front, no sound is emitted.
We also replaced the the head unit and that did not fix the problem.

However, we recently had to replace one of the rooftop drainers down behind the glove box, and to get to that we had to remove that hub with all the different connections running into it. Beforehand, sound was coming out just fine from both front and rear, but afterwards only rear was functioning. It probably has something to do with that maybe?

 

Well yes - if it worked before messing with connections, then definitely re-check all those connections
Your problem is most likely there

 

All the audio likely comes from the amp under the front passenger seat. I think only the most basic LR3s had audio to the speakers from the head unit itself, maybe? In any case, the wires for the front speakers do in fact run along the rockers and up into the dash by the kick panels. So tend to agree, you likely disconnected something.