Why does my engine belt squeal when I turn on the heater blower?

A squealing engine belt when you turn on the heater blower could indicate that the belt is worn, loose, or misaligned, causing it to slip under increased load. The blower motor requires additional power, putting extra strain on the belt. It’s advisable to inspect the belt for signs of wear and to check the tension and alignment to ensure proper operation. If the issue persists, consulting a mechanic may be necessary to avoid further damage.