Audio Systems: After market car stereo installation, car stereo installation, mercury sable

Question
Hi,
We are attempting to install a Pioneer C.D. player into a 1987 Mercury Sable with the 6 speaker premium system.
We bought the adapter harness but only the dash and rear deck speakers work.The door speakers do not.
Do you think you can help us figure this out?
Thanks very much,
John Nielsen -  

Answer
You probably have the wrong wiring harness or somehow it is wired wrong.

Possibly following the wiring chart found here:

http://www.modifiedlife.com/1987-mercury-sable-car-audio-wire-diagram/

will guide you to getting the right wires to the correct speakers.

Hope this helps.