If you installed an aftermarket radio in your Acura TSX Base model but the subwoofer isn’t working its because most likely you are missing this harness. This harness plug in behind the radio and gives you an RCA to connect to the subwoofer output of your radio. That signal is then sent from your aftermarket radio to the factory amplifier and finally to your subwoofer. In order for this harness to work you must connect the blue wire on the primary power harness you have to the remote wire of your aftermarket radio so your factory amplifier turns on.
