Jayco Alante – AC Capacitor & Fan Motor Service

Your Jayco Alante’s owner’s manual won’t mention it, and the service department charging you $400 in labor won’t explain it either: the rooftop AC unit’s most common failure has nothing to do with refrigerant or compressor wear. It’s a capacitor—a small cylindrical component that costs less than a tank of propane but makes the difference between a livable rig and an oven on wheels. I’ve rebuilt AC systems on dozens of Alantes, and I can count on one hand the times the actual compressor or motor was the culprit. What kills cooling is simpler and cheaper than anyone wants to admit. This breakdown walks through exactly how to diagnose whether you’re dealing with a failed capacitor or a burned-out fan motor, then how to pull and replace each one without calling a dealer or parking your rig in a service bay for three days. Both jobs take an afternoon, cost under $100 in parts, and are straightforward enough that you’ll wonder why anyone pays shop rates for them.

The Run Capacitor: The $20 Component That Restarts Everything

When you flip the AC switch and the compressor hums but the fan blade doesn’t turn, or it struggles to spin before stalling, the run capacitor has typically lost its charge after years in 140-degree attic heat. This single part is what bootstraps both the motor and compressor into sync—when it fails, one runs and the other doesn’t, and you get no cooling despite the system drawing power.

Parts and Tools

• Replacement run capacitor matched to the microfarad and voltage rating stamped on the old one (typically 60/5 MFD for Dometic units in the Alante) — check current price
• Replacement fan motor assembly if the original motor is burned, seized, or shows no continuity across its windings — check current price
• Needle-nose pliers or small wire strippers for disconnecting spade terminals from capacitor and motor leads
• Multimeter set to capacitance mode (or ohms mode for motor continuity testing)
• Flashlight or headlamp for visibility inside the AC shroud on the roof
• Small adjustable wrench or socket set for removing mounting bolts holding the capacitor or motor bracket
• Electrical tape and marker for labeling wire connections before disconnection

Step-by-Step Instructions

Step 1: Kill power to the AC unit at the breaker

Locate your RV’s main electrical panel and flip the breaker controlling the rooftop AC to the OFF position. Wait 30 seconds, then use a multimeter set to AC voltage to confirm no power is present at the AC unit’s terminal block on the roof. This prevents shock and protects components during diagnosis. Do not skip this step—capacitors hold charge even after power is cut and can deliver a painful shock.

Step 2: Access the AC shroud and photograph the wiring layout

Climb onto the roof and locate the Dometic AC unit. Remove the four bolts holding the plastic shroud cover and lift it away. Before touching anything, photograph the spade terminal connections on both the capacitor and motor with your phone. This image is your wiring map—you’ll need it when reassembling. Note which wire connects to which terminal (typically labeled C, H, and F on the capacitor).

Step 3: Test the capacitor with a multimeter

Set your multimeter to capacitance mode. Disconnect the spade terminals from the capacitor using needle-nose pliers. Touch the meter probes to the capacitor terminals and read the microfarad value. A failed capacitor reads zero or shows no change when you touch the probes. Compare the reading to the rating stamped on the capacitor body (usually 60/5 MFD). If the reading is significantly lower or zero, the capacitor has failed and needs replacement.

Step 4: Test the fan motor for continuity if the capacitor reads good

If the capacitor tested within spec, the motor itself may be burned out. Disconnect the motor’s spade terminals. Set your multimeter to ohms mode and touch the probes to the motor’s two main terminals. A good motor shows 5–15 ohms of resistance. A reading of zero (short) or infinity (open circuit) means the motor windings are damaged and the motor must be replaced. A burned motor often smells like charred plastic—trust your nose as a secondary indicator.

Step 5: Remove and replace the failed capacitor

If the capacitor failed, use a small wrench to remove the single bolt holding its mounting bracket to the AC frame. Slide the capacitor out and disconnect its spade terminals. Install the new capacitor by reversing the process: insert it into the bracket, secure with the bolt, then reconnect the spade terminals to their original positions using your photograph as reference. Ensure terminals are fully seated and not loose.

Step 6: Remove and replace the failed fan motor if needed

If the motor failed, remove the three bolts securing the motor bracket to the AC housing. Disconnect the motor’s spade terminals and slide the motor assembly out. Install the replacement motor by reversing the process: position it in the bracket, secure with three bolts (hand-tight, then snug—do not over-torque), and reconnect the spade terminals to their original positions. Verify the fan blade spins freely by hand before reassembling.

Step 7: Reassemble the shroud and restore power

Replace the plastic shroud cover and secure all four bolts. Climb down from the roof and return to the electrical panel. Flip the AC breaker back to ON. Wait 10 seconds, then climb back to the roof and listen for the compressor and fan motor to engage. The fan blade should spin smoothly and continuously. Feel for cold air exiting the interior vents. If both motor and compressor run and cooling resumes, the repair is complete.

What works

• Fan blade spins freely the moment power reaches it—no more that hopeless humming sound while you wait for it to catch.
• Refrigerant circulates properly again because the compressor and condenser fan are running together, dropping inside temps to livable levels within minutes.
• Bolts directly onto Dometic-brand units installed in Jayco Alante models—no hunting through cross-reference charts or contacting multiple suppliers to confirm compatibility.

What doesn’t

• Third-party marketplace sellers sometimes package these with rough handling—always look for corrosion or bent terminals before installation.
• Swapping in a new capacitor won’t resurrect a fan motor that’s already burned out internally—you’ll install it, power on, and still get silence instead of a spin, which costs you two days of troubleshooting before the real problem becomes clear.

I second-guessed myself the first time because the humming sound was so distinctive I was sure the motor was seizing, not that a tiny plastic cylinder was the culprit. Order the Fits for Dometic 3312195.000 Air Conditioner RV AC Motor Capacitor 60/5 MFD, Heavy Duty Air Conditioner Capacitor Replacement, Compatible with Dometic 3312195000 RV Air Conditioner Models and have it on hand before you climb on the roof.

This post contains affiliate links. As an Amazon Associate, I earn from qualifying purchases at no extra cost to you.