new radio put in but no sound in the speakers..

the new radio had connections for front and rear speakers. the original radio only had right and left wires to the radio.

since i seemed to only have one 'set', i just connected the new radio's 'front' wires to the old radio's left and right.

what did i do wrong? does the fader have something to do with this?

ps. i also posted this on the multimedia forum without a response so I am hoping that someone here could help

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Ben
1987 190d 2.5Turbo