New radio, no sound?

[chevync]

Just installed a new Kenwood head unit, my tahoe doesn't have steering wheel controls etc. I hooked everything everything right, double checked, triple checked, still no volume. Head unit lights up its picking up radio stations just no sound. There was a third harness hooked to the old radio I was thinking its from the old onstar. Also found another one not plugged in behind that one. Any ideas???

 

[YukonXL04]

Got any pictures of your wiring harness?
Also sometimes those radios have a feature to turn off the internal amplifier. Check that as well

 

[chevync]

Had to wire my blue remote wire to the pink wire in the third harness to turn the factory amp on. Works great now! Now I need to replace my stock speakers and add a sub, the other owner removed the stock sub so not alot of sound.