1999 s80 Left audio issue
 

Not sure what to check first and where. Very new at this car thing (first car) and I'd like to see if I can fix this myself.
Model: 1999 Volvo s80 T6 w/HU-611
Issue: Left speakers aren't producing any sound. Nothing at all. My father has bought a new amp under the passenger seat, so I assume it isn't that.

Any ideas where to look first?:confused:

This might be a stupid question, but did you check on the dash controls to see if the balance may be turned all the way to the right?

Best,

Sherry

Checked Balance left and right.

Any help?