Hi, I've got a 1989 GT with the stock original radio/cassette player. When I have the radio on it'll play perfectly fine on both sides on all speakers. The problem is when I go to play a cassette/bluetooth cassette it'll only play on the right side. I've tried cassettes that I know myself work just fine with no luck, and I have the balance adjuster in the middle as it should be too. Any help would be appreciated! - Thanks Vince.