get a mutlimeter and check to make sure you have 12volts at the Remote turn on when the Radio is on. you can take your multimeter also and hook up one lead to the center conductor and the other to the outer conductor set the meter on AC and turn the stereo up.. Also make sure your non fader output is turned on if the headunit has it if your connected to that. What kinda amp do you have anyhow?

99% of the headunits out there ar .75volts to 16volts(balanced) I blew the inputs on a Vega series amp onetime it looked like it was on but nothing worked. Bad Tranistor cuased it..
Any questions post or pm