Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, bear with us; re-confirm and post back with the complete model / series of the Acoustimass. Bose Acoustimass 5 series 3
Still, please click HERE for the wiring pinout of a 5-pin DIN used by Bose on some of its other models.
Alternatively, manually power on the Acoustimass. With a straightened paperclip end probe the inside of the DIN 1 pin at a time. The left and right lines would produce a humming sound.
Any developments with the project?