On my 79SB with factory air, I'm having a problem with where the air comes out (I think). When I set the A/C to normal, it comes out both in the dash vents and below in the outlet by the tranny hump. Shouldn't that only happen on the Bi-level setting or Maximum setting (guessing on this one)? I see that there's a diverter valve next to the floor outlet. If this is not working right, would that be the cause?