I just got finished installing an Alpine CDA-9856 I had from a previous (in dash dvd coming after more mods), anyways, I bought the harness that allows me to keep on using my stock shaker 1000 subs and amp. Only problem is when the radio turns on, I get like a boom noise, like you can hear the amps and system come on. I had this problem in my jeep and they said aftermarket HU, do not interact well with stock amps. So I disconnected the stock amp in my jeep and bam, problem solved. I was told though that this harness will allow me to use the factory subs and amp and not give me that same problem, but it's doing it again now in my mustang. Is this true ?? or is something else wrong. This is not my first install and yes all my wired are connected correctly and securely via solder. But really i'm stumped on this.

Thanks....BIB

 

You have probably already found the answer elsewhere, but you need to put a 5v voltage regulator between the 12v amp on from the head unit and the amp on wires going to the shaker amps. You can pick one up at Radio Shack for a couple bucks. Those shaker amps don't like the 12v!