the harness should be color coded. Sometimes the wires are even labeled as to which one it is. Obviously there are 4 pairs of wires. White should be left front, grey should be right front, green should be left rear and violet should be right rear. The solid wire is (+) and the one with the black stripe is (-). Thats the way it is on my pioneer and i am making the assumption there is some sort of industry standard. You could always just hook everything up and then use the HU fade function to figure out which ones you have to change. As for which speaker wire is going to which speaker....well i labeled mine when i ran them, so if you didn't you may just have to go for trial and error, checking with the fade function. You could probbly use a volt meter to run conductivity to figure it out as well. Might need an exta set of hands for that one.