PAC ROEM-FRD2 Wiring Interface

This interface lets you KEEP the factory amp. The new stereo will work without this interface but WILL BYPASS the factory amp and will use the receiver's built in amp. So I bought one of these for reduced price after purchasing a new Pioneer receiver from Crutchfield for my F150. My old truck had a built in amp stock to the truck and I was not sure that the new receiver would have enough power to give me a full sound. After first installing the new receiver, the speakers rattled and the sound was not great so I ordered this product as a possible fix because it was cheap enough. What I discovered was that the rattle was due to the old speakers literally falling apart from age! I put in 4 new speakers and the sound was quite decent for my purposes and I never actually installed this interface because I was happy with the new sound using the wiring that was provided. I hope this helps.