HVAC Motor Not Starting or Running Weakly? Rotom Run Capacitor 36-5J370 - Restore 5MFD Motor Run Capacitance

A defective motor-run capacitor is one possible cause of weak or unsuccessful motor starting in HVAC systems. The single-value run capacitor provides continuous phase-shift support to keep the motor running efficiently. When it fails, the motor may hum, struggle to reach operating speed, run intermittently, or overheat.

Common service component in residential and light-commercial HVAC fan motors and blower motor applications.

Part 36-5J370 is the Rotom specification-based replacement rated at 5MFD and 370 VAC that may restore proper motor-run support when testing confirms the original capacitor is defective and no related motor or electrical fault remains.

Is This the Right Part?

Confirm MFD, Voltage, Shape and Dimensions before ordering. This is the correct specification match if ALL of the following are true:

• Your original capacitor is rated exactly 5MFD - capacitance must match exactly
• Your original capacitor is rated 370V - a 370/440V or 440V replacement may also be used; a 370V-only capacitor must not replace a 440V application
• Your application uses a single-value oval run capacitor - not a dual-run capacitor and not a start capacitor
• Your mounting space accommodates an oval body approximately 2.03in wide, 1.24in deep and 1.58in high

Not sure? Send us your capacitor label specs - we will confirm before you order.

Common Symptoms of a Failed Motor-Run Capacitor

• Fan or blower motor hums but fails to start
• Motor starts weakly or struggles to reach full operating speed
• Motor runs hot or trips on thermal overload
• Capacitor body visibly bulged, leaking, or reads out-of-tolerance on a capacitance meter

If these symptoms match and capacitor testing confirms a defective reading, this is a likely failed component. Similar symptoms may also result from wiring, relays, contactors, motor winding failure, or electrical-supply faults - confirm the capacitor is the root cause before ordering.

Part Details

• Part Number: 36-5J370
• Brand: Rotom / AllTemp - New
• Type: Oval Single-Value HVAC Motor-Run Capacitor
• Capacitance: 5MFD / 5 uF
• Voltage Rating: 370 VAC
• Shape: Oval
• Width: 2.03 in (51.5 mm)
• Depth: 1.24 in (31.5 mm)
• Height: 1.58 in (40 mm)
• Features: Heavy-duty compact construction, built-in interrupter, UL and cUL Recognized
• GTIN/UPC: 777980008127
• Availability: In Stock
• Compatibility: Specification-based - match capacitance, voltage, shape, and dimensions to original

Also Replaces These Part Numbers

Direct 370V oval replacements (5MFD, 370V, oval):
12005 (MARS Blue Box), 12905 (JARD/MARS), 14005 (MARS USA), POC5 (Packard), POC5A (Titan HD), TOC5 (Titan Pro), CR5X370 (Supco), C305L (Genteq/Capcom), 27L570 (Genteq/Capcom), 27L570BX (Genteq/Capcom), 97F5705 (Genteq/Capcom) - electrical rating and oval shape match; case dimensions vary. Confirm mounting strap, available height and terminal clearance before ordering.

Higher-voltage oval replacements (5MFD, 370/440V or 440V, oval - valid upgrade):
36-5-370440 (Rotom), POCF5A (Titan HD), TOCF5 (Titan Pro), CR5X440 (Supco), 45050H (DiversiTech), 12029 (MARS Blue Box), 12929 (JARD/MARS), 14029 (MARS USA), P291-0504 (Totaline/Carrier) - 5MFD capacitance matches exactly; higher voltage rating is a valid replacement for a 370V application. Confirm case dimensions and mounting fit before ordering.

Electrical equivalents - round case (confirm mounting fit before ordering):
36-5R3744 (Rotom, round), PRCF5A (Titan HD, round), TRCF5 (Titan Pro, round), CR5X440R (Supco, round, 440V), 14105 (MARS USA, round, 440V), PRC5 (Packard, round, 370V), TRC5 (Titan Pro, round, 370V), CR5X370R (Supco, round, 370V), 14095 (MARS USA, round, 370V), C305R (Genteq/Capcom, round) - electrically compatible; round case is not a mechanical drop-in for an oval mounting bracket. A different mounting strap or bracket may be required.

Installation

Skill Level: Advanced - Qualified HVAC Technician Required. Disconnect and lock out all power before opening the electrical compartment. HVAC capacitor diagnosis and replacement should be completed by a qualified technician. Photograph the original wiring before disconnecting. Connect the replacement to the same terminals and confirm all connections are secure before restoring power and testing motor operation.

Specification Compatibility

This capacitor is compatible with any HVAC motor application that requires an oval single-value run capacitor rated at exactly 5MFD and 370V, provided the oval body (2.03in wide x 1.24in deep x 1.58in high) fits the existing mounting bracket. A 370/440V or 440V capacitor rated at exactly 5MFD may also be used. Compatibility is determined by electrical specification and physical fit - not by equipment model number. Contact us with your original capacitor label before ordering if you are unsure.

Pro Tip