89 Volvo 740 Wiring Help

i know a little buit about car stereos and with the help of this site have been able to install two, but this one has puzzled me. he has a 1989 Volvo 740 GLE station wagon. the factory finally craped out on him, he had a CD player from a previoud acr the he totaled. it workd fine. i have been able to hook up the constant and swiched power, the ground and the antena wore so that it will go up when the stereo is on. so all that is left is the speakers. there are only 3 wires left which has me very confused when i thought that it would require 8 to get all 4 speakers working. there is a yellow/white. blue and white wire left. i have looked up what should be there but come up empty. that is all that was conected to the stereo. there was also a plug with 6 contacts at the end of it. was this used for the speakers, it looks similare to something that would be used for a Cd changer, but its not.

any help would be apreciated, thanks you

Davis

bigdbronco@yahoo.com

1985-93 Volvo 740 Series Stereo Information

The factory amp is located under the steering column, just to the left. it's silver in color and has a round din cable and a rectangular black plug with quite a few multi color wires in it. leave the round cable, but pull out the rectangle one. the wires running to your rear speakers will be found in here. Here is the wiring color codes:

hope that might help you?

-Will