南 may have started as a picture of a bell or a hanging instrument that faced south in ritual. Whatever its origin, it has meant 'south' for millennia — the warm, sunny direction in the Northern Hemisphere, the way temples and homes traditionally face.
南 is south — and direction matters enormously in Chinese culture. By feng shui, the best homes and palaces face SOUTH (坐北朝南, 'sit north, face south') to catch warmth and light; the emperor's throne faced south. Note the Chinese ORDER of directions differs from English: they say 东南西北 (E-S-W-N) or 南北 (south-north), where English says 'north-south'. 南方 = the South (of China), known for rice, rain, and a gentler climate.
The warm, sunny direction temples face — SOUTH.
Chinese palaces 'sit north, face south' (坐北朝南) for sunlight and warmth — south is the auspicious direction. And Chinese lists directions as 东南西北, not 'north-south' like English.