Loop Sheets and set Cond. Format to a Range of Cells?

I'm trying to loop all the visible sheets in a workbook, then set a Conditional Format to a range of cells on each sheet. The code below works for me, but only on the first sheet. I can't seem to get it to work on the rest of the sheets. Any suggestions would be appreciated.
Thanks!

Sub CondForm3()
Dim r As Range
Dim wksheet As Worksheet
Dim n As Long

For Each wksheet In Worksheets
           If wksheet.Visible = True Then
            n = n + 1
            End If
    Next wksheet
For i = 1 To n
  
Set sh = Worksheets(i)
Set r1 = sh.Range("AC11:AC37")

    For Each r In r1
    
'r1.Select
    Application.Range("AC11:AC37").Select
    Selection.FormatConditions.Delete
    Selection.FormatConditions.Add Type:=xlCellValue, Operator:=xlGreater, _
        Formula1:="=$AB$9"
    Selection.FormatConditions(1).Font.ColorIndex = 3
    Selection.FormatConditions.Add Type:=xlCellValue, Operator:=xlLess, _
        Formula1:="=$AC$9"
    Selection.FormatConditions(2).Font.ColorIndex = 3
    Next r
    Next

End Sub