If you dont have a schematic then you can use this "old technique". Get a 1.5 volt AA battery and solder (or attach) a wire jumper on each end of the battery. Unplug the connector from the speaker and choose a terminal off of the factory speaker and put the + of battery on one and "pop" the second terminal for a brief second with the - and if the cone moves upward for that brief second then you have found the + terminal of the speaker. if the speaker cone moves inward then the + is on the other terminal. Once you figure out which terminal was the + one that made the cone travel upward then you find out which wire on the connecter coresponds with the connector on the terminal that was the + lead and that will be your + wire on your factory system. I learned this trick in the late '80s when we didnt have access to wiring schematics or internet, its an old trick but still works today. Good luck.
