Amplifier works but when engine is running it stops working

[300k_Saturn]

I used a fuse tap on the cigarette lighter which leads to an amplifier. The amplifier works when the car is off but the minute the engine is running the amplifier no longer outputs audio it is still turned on as there is a light showing it turns on but otherwise it does nothing else. On the fuse tap o have a 15 a fuse (the standard fuse for the cig lighter) and a 10a fuse. Any idea how to fix this?

This is the amplifier I am using is: Pyle PFA300