Hello so I've purchased a car used and no inputs work other than just the plain radio the Bluetooth works the gps works but when you go to try and select an input there all greyed out except a.m f.m radio even the aux card doesn't read no sd card and I haven't tryed USB yet is there any thing I should check as far as wiring gos?? I've done a factory reset same problem as well as the processor reset? Thanks for your help