Anyone know where I can get the pinouts for the radio connections for a 91 Nissan Maxima? My buddy is trying to install a stereo, and we have the manual from the old radio, the manual from the new one, but not the car. Normally it wouldn't be a problem, but somewhere something is crossed on the old radio (not stock) harness, and there are four black wires, two yellows, two blues, it's a mess.