If the wires have not been moved and are still connected, there are 2 possibilities.
1) The speakers are both blown (not likely)
2) The receiver is in “protect” mode which will shut off all output. (most likely)
Protect mode is where the receiver turns off the outputs to protect the speakers from damage. This usually occurs because the output stage fails. In your case I would suspect that the output IC has failed and requires replacement. I am assuming that you have a Kenwood KDC-255U.