The Dometic Duo-Therm AC Motor Capacitor (Part# 3313107.028) is a dual-run capacitor rated at 20/10 MFD, designed specifically for Dometic and Duo-Therm RV air conditioning units. This capacitor provides the electrical boost needed to start and run both the compressor and fan motor in your rooftop AC system. If your RV air conditioner won't start, runs intermittently, or the fan motor hums without spinning, a failed capacitor is often the culprit—and this is the exact replacement part you need.
Key Features
- Dual-Run Design: 20 MFD for compressor start/run, 10 MFD for fan motor operation—two capacitors in one compact housing
- OEM Dometic Replacement: Factory-specified part engineered to exact tolerances for Duo-Therm air conditioners
- High-Temperature Rated: Built to withstand the extreme heat conditions inside RV rooftop AC units during summer operation
- Direct Fit Replacement: Mounts in the original capacitor location with existing wiring harness connections
- Reliable Performance: Restores proper compressor and fan motor operation for consistent cooling
- Easy DIY Installation: Most RV owners can replace this capacitor in 15-20 minutes with basic tools
Technical Specifications
| Part Number | 3313107.028 |
| Capacitance Rating | 20/10 MFD (Dual Run) |
| Voltage Rating | 370 VAC |
| Application | RV Air Conditioner Motor Capacitor |
| Compatible Brands | Dometic, Duo-Therm |
| Terminal Configuration | 3-Terminal (Common, Compressor, Fan) |
| Operating Temperature | -40°F to 185°F |
Compatibility Information
This capacitor is designed for Dometic and Duo-Therm RV air conditioning systems. To verify compatibility, check your existing capacitor for matching MFD ratings (20/10) and voltage (370V). The capacitor is typically located in the electrical compartment of your rooftop AC unit, accessible by removing the interior ceiling assembly or outer shroud.
Frequently Asked Questions
How do I know if my AC capacitor has failed?
Common signs include: AC won't start at all, compressor hums but doesn't run, fan won't spin, AC trips the breaker repeatedly, or visible bulging/leaking from the capacitor body. A multimeter can test capacitance, but visual inspection often reveals obvious failure.
Can I use a different MFD rating if I can't find the exact match?
No—always use the exact MFD rating specified by the manufacturer. Using incorrect capacitance can cause motor damage, reduced cooling efficiency, or complete system failure. This 20/10 MFD rating is engineered specifically for your Dometic system's electrical requirements.
Is this repair safe for a DIYer, or should I hire a technician?
With proper safety precautions, this is a manageable DIY repair. CRITICAL: Always disconnect shore power and wait 5-10 minutes before touching any wires—capacitors store electrical charge even when power is off. Discharge the old capacitor with an insulated screwdriver across terminals before removal. If you're uncomfortable working with electrical components, consult an RV technician.
Will this capacitor fit other brands of RV air conditioners?
This is a Dometic OEM part designed specifically for Duo-Therm systems. While the electrical ratings (20/10 MFD, 370V) may match other brands, mounting configuration and terminal placement vary. Always verify your existing part number or consult your AC unit's wiring diagram before ordering.
Why Choose Elkhart RV Parts?
We specialize in hard-to-find Dometic and Duo-Therm replacement parts that keep your RV systems running. Located in Elkhart, Indiana—the RV Capital of the World—we understand the urgency when your air conditioning fails on a hot summer trip. We stock genuine OEM parts and ship fast so you can get back to enjoying your travels. Our team knows these systems inside and out and can help you identify the exact part you need. When you need it done right the first time, trust the Dometic parts experts at Elkhart RV Parts.
| Brand | Dometic |
|---|---|
| Product_line | Duo-Therm |
| Part_number | 3313107.028 |
| Product_type | AC Motor Capacitor |
| Capacitance_mfd | 20/10 |
| Part_category | OEM Replacement |
| Compatible_models | 1350015000 |
| Application | RV Air Conditioning |
| Function | Motor capacitor for AC compressor startup |
| Condition | New |
Factory-Fresh OEM Parts — the same brands installed in new RVs straight from Elkhart. Genuine, name-brand components made to order — never generic, never outdated. Sourced directly from the original RV manufacturers for perfect fit and factory-level quality.