I have upgraded the headunit in my 94' Mazda 323 Astina GXEI to be able to plug my iPod in (from a standard Pionner system to a Pioneer DEH-1950). It was a straight swap and it all went fine till Yesterday:

When i turned the unit off, the antenna automatically retracted but made a very weird continuous bumping noise once it got to the bottom, like it was trying to go further. Then when i turned it back on, the sound was only coming from one side of the car, then today the sound was missing vocals or sounded like if i was using the radio with a bad reception.

Any advise would be greatly appreciated, cheers.