Hey guys. I'm new to the forum and need some help.
I have an 03 xj8 sport. I would like to keep factory head unit in dash. But would like to install my infinty kappa amps and speakers.
Does the factory system use an external amp that I need to by-pass? Or do I wire in line converters behind the head unit?
Please help.

Thank,

 

yes, use of LOC will do the job but make sure there are no transformers inside, but just resistors. Or simply built your own like the one I attached. (left side is radio side, right side is external amp)

there is no common ground, and there shouldn't be a common ground on the inputs of your infinity amp either so everything is OK to go.