So far the way i have my sound system set up is my head unit, a pioneer deh-x4800bt, replacing the original OEM receiver from a Pontiac G5 GT 2008 with aftermarket speakers connected to the AM receiver. Note: the car had a factory amp that I removed in case that has anything to do with the issue. I tried wiring the aftermarket receiver to the original OEM’s wires but no sound would come out of the speakers, however the aftermarket stereo would still power on. Then, I connected the speakers wires from the factory amplifier to the pioneer receiver. However, no sound just power. So instead I decided to hardwire the corresponding wires from the aftermarket receiver to each individual speaker’s negative and positive in the vehicle rather than the wires from the original stereo’s harness and from the factory amp. I was successful in getting sound hooray but here comes my next problem. The installing of my aftermarket amplifier. Let me give some background info: the amp is a Pioneer Gm-6400f 4 channel with 600 hertz. I’m on a budget but also brand matching.I got the amp for 50 bucks on offerup , was told it works and I took the guys word for it. The amp powers on and seems to work fine. But the problem begins with me trying to add the amp to my system and getting no sound when I connect one speaker to it. First off, I have the amp set up with a 50A fuse block, 8 gauge wire, battery in the truck, amp mounted behind a seat, amp turn on wire attached to a fuse in my car’s fuse box, device is grounded, and proper 16gauge speaker wire for the channels. The amp turns on when I power the vehicle which must be a good sign. To my understanding, the way an amp can be added to an AM system is by connecting the Amp’s RCA’s to the AM receivers outputs and wiring your speakers directly to the amps channels? I tried amplifying one speaker to a channel to see if it would work but what happened instead was no sound from ALL speakers was the outcome. When I disconnect the wire from the amp to the single affected speaker, the speakers all regain sound except the disconnected speaker. Again, car has a factory amp but I managed to bypass by wiring the speakers directly to the Aftermarket receiver. How do I go about wiring my amp with the receiver and speakers without losing my sound?