Are you talking about the wires for the speakers only, or just that there are 4 wires only? As far as positive and negative, you can switch it at the speaker. It will work either way. I use a 9v battery to locate with wires go to which speaker., When you connect it across the battery, the speake will make a pop sound Dont hold it on it, just touch it. The thing I have found in the past is hook up you speakers, and when the radio is on, take one speaker, take note to the way it sounds, and then reverse the positive and negative wires. Listen again, and leave the wires connected in the way the speakers sound overall. I forget the term used, but basically its phasig the speakers for best sound. You can repeat the process for the two front ( if installed) and so on.