Ziggaty

My Mark Levinson amplifier in the trunk of my 2008 GS350 is not working correctly. with some speakers not working. There is a single wire that goes to the amplifier in the trunk that appears to be internally broken 6 inches from the amplifier. This single wire cable plugs into the bumper bar end of the amplifier. My question is; Is it possible to strip the insulation back and solder it or is it a coax type cable that will need a car HiFi shop to repair it? Help Please.