What causes a whirling noise under dash floor in 1997 Toyota t100?

A whirling noise under the dash floor of a 1997 Toyota T100 could be caused by a few issues, including a malfunctioning blower motor or a problem with the fan assembly. Debris caught in the blower motor can also create noise as it spins. Additionally, issues with the heating or air conditioning system, such as a failing actuator, may contribute to the sound. It's advisable to inspect these components for any signs of wear or obstruction.