Aftermarket radio, power but not sound
Trying to install aftermarket Head Unit and Amplifier. Got wiring kit, everything soldered and taped good. When I go to hook the radio clips to the factory radio clips, I get power on my radio but no sound out of speakers. Tested speaker leads off head unit with another speaker(just to test HU) got sound, (but nothing out of original truck speakers). Grounded after market HU to the clip that was hooked to the back of the factory radio.
Hooked the factory radio back up, it worked like normal. One thing I did find out is that the factory radio does not even power on, unless the antenna is hooked-up.
Do I need a antenna adapter for aftermarket head Unit? The amplifier works, got bass, but no sound out of factory speakers. Any ideas, please help