1990 525i

I need held figuring out the speaker wires for this thing, im putting a aftermarket stereo in and its killing me. I connected what I thought were the wires but nothing. I got it to power up. ive looked and looked for the wiring diagram and nothing. if any one could help me out or point me in the...

i have a 90' 525i with 97xxx miles on it. i bought for cheap (500) with the hopes that this problem was small. both the spark plugs and oil show no signs of coolant, but the oil in the radiator is outstanding. the car runs smooth, and recently the previous owner put in a new radiator...