Why is my cassette adapter playing on only the left side speakers of my car?

I have an iPhone and I have been playing music through my adapter for a few months and a few weeks ago it just plays out of the left speakers and sometimes it flickers to the right, it worked fine before, but why is it doing this now?

You have to play with the speakers abit ( the buttons that control the audio ) it will help

It is just the cassette head that is getting old or damage, the radio was made to play 22minutes per side tapes not the device you have, some have sensors to protect the radio or tape film if there was a problem most likely that is switching from side to side, a new tape adapter might help but it will be better to purchase an auxiliary audio input interface for your radio