1987 ford thunderbird wiring color

i need to know the wire colors for a ford thunderbird.  Also, there are four wires for each rear speaker. Can anyone tell me why this is?

The last Thunderbird that I worked on had 5 x 8 speakers and there were only 2 wires on each speaker, but most of the time when there are 4 wires, it is because one set supplier the tweeter and the other supplies the woofer. Your car may ( may or may not ) have the factory amp as well. You will know when you try to hook up a deck and everything works except no sound.

Hi titleistduval, here's the stereo wiring info I have for an '87 Thunderbird: https://www.the12volt.com/installbay/detail.asp?info=alarm&year=1985-88&make=Ford&model=Thunderbird&ID=17851&type=Stereo 

Are your rear speakers stock or aftermarket? If they are stock, it's likely you have a factory amplifier installed, but are you installing a new head unit or amplifier or both? Let us know and we'll try to be more helpful.

the12volt

It is actually not my car, it is my g/f's car and she just wants me to put the stock speakers back in because she is gonna sell it.  Nothing was done except that there were aftermarket speakers in the rear.  The people who put them in cut the wires and only used two out of the four on each side.  Only one of them worked.  I think that two of them connect to the positive and the other two are for the negative.