After tearing apart my 1500 today I am finding that under the seat there is a rubber holder that has 3 unused connectors that do NOT connect to anything. One of these connectors (FEMALE END & BLK in color w/white cap) has 4 wires. These wires match up with the schematic wiring. This meets up in front next to the CB on the right side that has a connector not in use (MALE END & BLK in color) with the same color wires. I was just told that Honda used to have a kit for the rear speakers that had a jumper that went from the front connector to the radio & the rear connector to the speakers. If you just tap into the front speaker wires the rear speakers don't come in too loud. I am looking for someone with more knowledge in this problem or with a schematic & or pictorial diagram.