1988 BMW 325 FUEL PUMP WIRE ORIENTATION

I installed a new fuel pump in my BMW. I had to solder new wires on, and assumed that red was positive (+) and Black was negative (-). I got everything hooked back up, turned the key over and waited for 10 seconds, and did not hear the pump start. Are these extra-quiet pumps, or did I wire it backward? I know there are other problems right now, but I still figured that pump would prime. PLEASE HELP

Ryan