i had a stock radio in my 99 ram bought a kenwood i hard wired all the wires and when i plug it in the radio will come on but nothing though the speckers and then when i plug the antenna in it goes in to protect, went to a audio place he said my speckers were bad bought four new ones and still nothing though the speckers and antenna is still going into protect mode any ideas?

 

Take the head unit out of the truck with a door speaker and go out to the battery under the hood or a battery charger and connect the Yellow and Red together and go to the (+) and the black to (-) and connect the speaker to each set of channel leads one at a time to test each channel.