2003 gmc sonoma car stereo/dash

I recently was helping my brother connect a new stereo in his Sonoma. But the problem is that when we connected everything back up the speedometer and Tachometer do no work. And after I connected all of the speakers I still had extra wires. I have looked all over the internet trying to find instructions but they don't have all of the wires that I see. And Also when I connected everything back up the stereo did not even receive power. I have also checked every single fuse in the truck and they are all fine. I don't know what I am missing.Man cannot put together that which he has not put together in a dream.

Truck Details: Make: GMC Model: Sonoma Cab: Crew Year: 2003Man cannot put together that which he has not put together in a dream.

Recheck your wiring as you have likely connected the wires incorrectly. Verify that the dark green wire in the harness (there is more than one) has 12 volts on it with the key on and 0 volts key off. This is your ignition wire. Use a meter to confirm any other wires as there are duplicate wire colors and connecting to the wrong ones which are on the data bus can damage the vehicle. Always use a correct wiring connector for the vehicle. They are cheap and save having problems liek this.sparky