It appears the Classic has the same issue as the Pro for me. When I tune Nav 1 frequency, Nav 2 tunes as well and at the same time. They are both set to the same frequency and can't be tuned independently.

I just noticed that Com 2, Nav 2 and ADF 2 controls have red lines through them. Showing them to be off. I emailed a picture of it to you.

The numbers with the red line over are the standby frequencies. Flip the TFR (transfer) switch to make the standby freq the active. NAV 1 and 2 radios are located on the glareshield next to the autopilot controls.

I was just wondering if that is what my problem is. I guess I never paid attention to them before.