Thermostat calls for cooling but only the indoor blower runs; outdoor Payne condenser does not start.

Safety first: Turn off power to both indoor and outdoor units before working on wiring. Beware of high voltage in the outdoor unit.

• Listen for outdoor unit: When cooling is called, check if the outdoor fan or compressor attempts to start. Silence suggests no 24V signal or a failed contactor.
• Check float switch: If your Payne air handler has a condensate float switch, inspect the drain pan and line. Clear any clogs and reset the switch if tripped.
• Inspect Y wiring: Verify the Y wire is secure at thermostat, indoor control board, and any splice to the outdoor unit.
• Test contactor coil (advanced): With power off, measure resistance across the contactor coil terminals. Replace the contactor if the coil is open.
• Check low‑voltage fuse: Replace a blown fuse on the Payne control board only after finding and correcting any shorts.
• Call a technician if unsure: Outdoor unit diagnostics involve high voltage and refrigerant components; professional service is recommended if basic checks do not resolve the issue.