No sound. I installed a Sony Xplod into my jeep cherokee bought an adapter wiring harness from

Question

I installed a Sony Xplod into my jeep cherokee bought an adapter wiring harness from Wal-mart, not first time installing radios. Turns on but no sound, i checked out radio on other car works fine. checked the wiring over and over nothing missed, wondering if harness is bad. help please.