chocolat1701
Dedicated LVC Member
Ok lets take it one step at a time. First in the back of the HU you probably used a wire harness since you most likely had the alpine audiophile system because you have rear deck speaker (FYI the cd changer was built into the HU if you have a 01 or higher if not it would have been in the glove box) first let's identify what wires you are using. You should be using do a search for wiring diagram here I think quick ls posted this we want to make sure that you are not already powering the rear deck amp and you are already sending a signal back there and then your amplified it by using the loc hence the pop sound when powered on. You can also just remove the loc and see if the rear deck still is working. Now if you do not get any sound after you remove the loc then just get a 14 Ft RCA cables please make it a good one bad just lower your back seat and test again using the new Rca. If the pop goes away then the old RCA wire s shorted or bent some where and just replace the wire with the new one. If you still getting a pop the then your loc is crappy but the good thing is that you can cut the heads of the RCA jack and splice it to the connector that is facing the cabin on the rear deck amp. That connector has the pwr/ground/remote turn on/left and right inputs just splice the rce to the left and right inputs and it will work no loc needed. I did this to my ls and my brothers ls or just get a new amp the rear decks are only 45watts you can find a cheap amp to power these for like 29 bucks in ebay.