I have a 2004 GS430. My navigation stopped talking to me. There is no voice guided navigation. However, the radio works fine. When the radio is on there is no sound coming from the driver's side door speaker. All other speakers work. Do I need a new speaker? Change a fuse? Change the amp?

 

Dunno. But at 15 yrs of age, it might be better just to upgrade to a double din with car play and even a new amp.
doubel din might run you $200 and a decent 5 channel amp $250 depending where you look on eBay..

good luck