2000 Mercury Grand Marquis Stereo Wiring

Yes I looked at the wiring diagram with colors listed on this site and many others; but, it does not match what is in my vehicle. All the speaker wires were correctly colored and twisted together for +/- as expected. However, I do not have a solid blue wire which lists as amp remote and I have three additional wires that are not listed. I am assuming these 3 are all grounds but I'm not sure if I should connect these three with the solid black ground wire. The three I have are black / yellow, black / lt blue, and black / lt green. There is no wiring harness plug to use an after market connector. The total number of wires on the vehicle are 15 (in a 16 pin connector) and on the after market radio, there are 12 wires. I have red, yellow, black, blue, and the 8 speaker wires. So basically I need to know if the blue/red goes to the solid blue or to the yellow/black for a switched connection and do I attach all BLACK/ ... together to the solid black.

Update: I found a site that lists colors for a police interceptor crown vic that appear to match my setup (minus one wire). I am going to try these connections and see if they solve the problem.

Still no go on radio working. Any suggestions?