Remote wire terminal reads 5. volts when plugged in

[barkingspider]

I have a RockfordFosgate T 2500 watt amp that's been hooked up for the past 5 years that has suddenly quit turning on. I did recently change the battery to the car so i wonder if somehow i shorted it. Ive checked all connections and fuses and still nothing.  Something strange I did notice is when the the remote wire isn't hooked up it reads 12 volts,  and the power wire reads 14 volts, but when its connected the remote wire terminal reads 5 volts and the power  wire  terminal voltage is almost cut in half. When the power wire is connected but the remote wire isn't the power wire terminal reads 14 volts like normal. What could be causing this?