New radio no sound, head unit working Deawoo Lanos

I have a 2002 Deawoo Lanos.

I removed my stock radio being very careful to mark and write down what each wire was. i hooked it up to the harnesses that come with the Boss radio according to my guide and those i have found online for this car. There is not a Stock amp/antenna to worry about so blue wire is not connected.

unit turns on , no sound through my stock speakers. All wires test out good with my probe, speakers hooked up to the back of the unit directly (no harness) work and i get sound. so my feeling is it is with the plug. The unit and plug are brand new (came with kit) could it be a bad plug or could it be my connections. i used standard blue wire connectors. could it be i need to solder then instead? or get a new plug, or????