I bought this truck used and the PO rewired the stereo and speakers all aftermarket. Anyway he didn't know with the Infinity system that there is an amplifier, so he never hooked it up. I have tested it and it still works, but i have no need for it as the aftermarket speakers sound good. It appears to sell on EBay for about 100 dollars, but I am up for reasonable offers as I am not sure what exactly it is worth.