Complete repair guide for the Grand Design Solitude – AC Capacitor & Fan Motor Service. Follow these steps to diagnose and fix the issue yourself.
Parts & Tools You’ll Need
- RV AC dual run capacitor (Dometic/Coleman-Mach)
- Rooftop AC fan motor
- RV AC thermostat / control board
- AC evaporator/condenser coil cleaner foam
- Rooftop AC shroud / outer cover
- AC roof gasket & self-leveling lap sealant
- Fin comb / coil straightener tool
- Non-contact infrared thermometer
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Step-by-Step Repair Guide
Step 1: Diagnose AC Issues and Safety
Start by identifying whether your Solitude’s AC is underperforming, making unusual noises, or failing completely—symptoms often point to a failing capacitor or fan motor. Before beginning any work, turn off power at your main disconnect switch, locate the rooftop AC unit, and allow it to cool completely to avoid electrical shock and burns.
Step 2: Remove Shroud and Access Components
Unbolt and carefully lift off the rooftop AC shroud or outer cover using a socket wrench, noting the orientation of any wiring connections for reassembly. Set the shroud aside on a clean surface where it won’t get damaged, as you’ll need to reinstall it once service is complete.
Step 3: Discharge and Replace Capacitor
Using an insulated screwdriver, safely discharge the existing dual run capacitor by touching the blade across both terminals to eliminate residual electrical charge. Unscrew the mounting bracket, disconnect the spade terminals, and install your new Dometic or Coleman-Mach capacitor in the same orientation, ensuring terminals are firmly seated.
Step 4: Inspect and Service Fan Motor
Examine the rooftop fan motor for debris, corrosion, or worn bearings that could cause noise or reduced airflow performance. If the motor is sluggish or non-functional after capacitor replacement, unbolt it from its mounting plate, disconnect electrical connectors, and install the replacement unit while noting the rotation direction.
Step 5: Clean Evaporator and Condenser Coils
Apply AC evaporator and condenser coil cleaner foam directly to the cooling fins and allow it to sit for the recommended time before rinsing with distilled water. Use your fin comb or coil straightener tool to gently realign any bent fins, improving heat transfer efficiency and reducing strain on the new motor.
Step 6: Reinstall Shroud with Proper Sealing
Position the AC shroud back onto the unit, aligning all bolt holes and reconnecting any disconnected wiring to the thermostat or control board. Apply a bead of self-leveling lap sealant around the base gasket and bolt points to prevent water intrusion and ensure a weathertight installation on your roof.
Step 7: Test AC Performance and Temperature
Restore power to your RV, set the thermostat to cooling mode, and allow the AC to run for 10-15 minutes while monitoring operation with your non-contact infrared thermometer. Verify that the fan motor runs smoothly, airflow is strong, and the supply air temperature is dropping to confirm the capacitor and motor replacement was successful.
Recommended Parts
| Part | Link |
|---|---|
| RV AC dual run capacitor (Dometic/Coleman-Mach) | View on Amazon |
| Rooftop AC fan motor | View on Amazon |
| RV AC thermostat / control board | View on Amazon |
| AC evaporator/condenser coil cleaner foam | View on Amazon |
| Rooftop AC shroud / outer cover | View on Amazon |
| AC roof gasket & self-leveling lap sealant | View on Amazon |
| Fin comb / coil straightener tool | View on Amazon |
| Non-contact infrared thermometer | View on Amazon |