What causes ac unit outside to stop and smell like it is burning?

If an outdoor AC unit stops functioning and emits a burning smell, it could indicate an electrical issue, such as a short circuit or overheating components. Dust and debris buildup on the unit can also cause overheating, leading to burnt insulation or wiring. Additionally, a failing compressor or other internal component may be overheating and producing a burning odor. It's essential to turn off the unit immediately and consult a professional technician to diagnose and resolve the issue safely.