If power is present but the output voltage is missing or communication between the indoor and outdoor units is fixed (not pulsating)

For 4-20mA

The CCWLE rotation (Counter-Clockwise Lead End) is specifically designed to match the factory airflow requirements of compatible Lennox condensing units

Direct Compatibility: Engineered specifically for Reznor UDAP and UDAS units

While mounting patterns may occasionally overlap with American Standard units

Loren Cook 520201 Shaft 320788-704 If power is present butThe Loren Cook 520201 Shaft is a critical OEM replacement part engineered for high performance HVAC air movement systems. Built to precise industrial specifications, this 16. 45 inch blower shaft features a 0. 74 inch (3 4") diameter designed to handle the torque and rotational loads typical of Loren Cook centrifugal fans and belt drive blowers. The 1018 or similar high grade carbon steel construction ensures minimal vibration and maximum power