Very Quiet Music out of front right, nothing else works!

There are a lot of questions to be had about this issue, so one at a time....1. Have you checked the connections to the speakers, and how many are connected? In other words, what is all connected to the head unit, and by what means...direct, amplified,etc.

The basic of what it sounds like is crossconnected wires on the left side which would cause the right side to play extremely low at even the highest volume. But if more than two speakers are connected, and how they are is what will make this a process.

If you can, take the step of setting the output on the headunit to play through one speaker at at time starting with the one making sound. But turn everything off after its setup and recheck the wiring from the source to the speakers, either direct or indirect. This would be the first place to start.

It may be that a speaker wire is not just closing the circuit early by positive to negative crossing, but may likely be grounded as well. Check all of that out first. You will likely need to disconnect each speaker and play something through the headunit, while only having one connected at a time.

if they still play nothing, then it could be a number of things after that. So, the best bet is to check all connections, and play each speaker at a time while the others are compleetely disconnected. If they all play independantly, its a grounded speaker cable or crossed connected cable. If none of them still play independantly during this, it might be an electrical issue within the headunit, unless another amplified source is being utilized, in which case you would want to reverify that it does not have a factory amp. So many variables for this situation, but process of elimination is the key.