'86 Corolla Seca wiring

Hi. I need help with wiring the audio for my 1986 corolla seca. My mechanic installed an aftermarket system, and he only connected the two front speakers. I removed the unit, and want to connect the rear speakers as well. However, i'm having problems with matching the wires. Could somebody perhaps provide a diagram with the correct wiring?

Radio 12v blue / YELLOW + radio harness     Radio Ground brown or WHITE/ black   -   radio harness      Radio Ignition gray   +   radio harness      Radio Illumination green   +   radio harness      Factory Amp Turn-on N/A            Power Antenna N/A            LF Speaker +/- pink - purple   +,- radio harness      RF Speaker +/- lt. green - blue   +,- radio harness      LR Speaker +/- black (blk/wht) - yellow (wht) +,- radio harness      RR Speaker +/- red - white (BROWN / red)   +,- radio harness