OP what I got from your post is probably what I've done. Your car most likely is equipped with Hifi stereo which mean the rear door panels did not come with speakers, however the previous owner before you probably swapped the door panels from a vehicle equipped with top hifi (logic 7) and just never wired the speakers to work. My car is equipped with Hifi, and I swapped rear door panels from a donor car to accommodate rear door speakers. I've yet to wire them up as well. I think the easiest route is to have them wired to the rear deck speakers. Just my guess tho.
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