OEM Carrier Single Run Capacitor P291-0303 / P291-0304 for Model MH1AJX018005AAAA

This is the factory-specified OEM single run capacitor for the Carrier MH1AJX018005AAAA air handler or mini-split system. A single run capacitor provides the continuous electrical charge needed to keep the blower or fan motor running at peak efficiency once it has started. When this capacitor begins to fail, you may notice the motor humming without turning, sluggish startup, intermittent shutdowns, or complete failure of the fan or blower to run — all of which can lead to compressor damage or system lockout if left unaddressed. Replacing this component promptly with the correct OEM part restores proper motor operation and protects the rest of the system.

• Specs: Single run capacitor | OEM Part Numbers: P291-0303 and P291-0304 | Factory-matched MFD and voltage rating | Round or oval case (confirm data plate specs before ordering) | ±3% tolerance to protect motor windings
• OEM vs Generic: This listing offers the genuine OEM Carrier capacitor manufactured to exact factory specifications. Generic capacitors often carry ±10% MFD tolerances, which accelerates motor wear, reduces efficiency, and can void equipment warranties. The OEM part ensures a precise electrical match every time.
• Install Difficulty: 2/5 — Always discharge the capacitor fully before touching any terminals (use an insulated resistor or discharge tool). Tools needed: 1/4" nut driver, needle-nose pliers, and a multimeter to verify the old capacitor has failed. Photograph all wiring connections before disconnecting to ensure correct reassembly.
• Warranty: Backed by a 1-year OEM factory warranty against defects. Orders placed before our daily shipping cutoff ship same business day from our stocked warehouse.

Compatibility: Designed as the direct OEM replacement for Carrier model MH1AJX018005AAAA. This model is an 18,000 BTU (1.5-ton) Carrier air handler unit. Both OEM part numbers P291-0303 and P291-0304 are single run capacitors — confirm the exact MFD rating and voltage on your unit's data plate before ordering to ensure the correct variant is selected. Have questions about fitment? Our HVAC parts specialists verify compatibility before you order — reach out via chat or phone and we'll confirm the right part for your specific unit.