If a technician reads 0 Ohms between the common and low speed wires on a 120 VAC furnace motor, what does this indicate?

When a technician reads 0 Ohms between the common and low speed wires on a 120 VAC furnace motor, it indicates a direct path or short circuit between those two wires. This means there is no resistance to the flow of current, which is characteristic of a shorted winding.

In a properly functioning motor, there should be a specific resistance value indicating the winding's integrity. If the reading is 0 Ohms, it suggests that the winding is not functioning as intended, possibly allowing an excessive amount of current to flow, which can lead to overheating and damage. A shorted winding usually results from insulation failure or other internal faults that compromise the winding's ability to operate correctly.

Understanding these electrical characteristics is crucial when diagnosing motor issues, as it allows technicians to identify problems early and take appropriate corrective actions before further damage occurs to the motor.