Hi

I have 2004 explorer with mach audio system. No aux obvi so I installed pioneer fh-x720bt. Wiring harness was metra 70-5521. Connection was with butt connectors.

Issue is that now only front left and back right speakers are working. Tried stock radio again and having same issue. When I cross the wires for the speakers that are out there isnt any static.

Any thoughts would be greatly appreciated