2002 honda accord amp problem

I am attempting to hook up a kicker 2 channel amp to my factory radio in order to power my rear 6x9's. I purchased a LOC placed it behind the factory radio and tapped it to the rear channel speaker wire output from the radio to receive a signal. I also grounded the LOC to the Source's Ground wire. I have an RCA cable running from the LOC to the amp and output speaker wire going directly to the rear speakers. What is weird is that when the speaker wire is connected to the amp my radio cuts off. Sometimes it even makes a loud humming or buzzing noise (but no music). When I disconnect the output speaker wires from the amp and turn the factory radio back on it works fine. I have been trying to figure this out for 2 weeks. Can some one tell me what I did wrong.

which wires are you referring to?

and how can i tell if they are grounding out?