Newmar Bay Star Sport – AC Capacitor & Fan Motor Service

Walk into a Newmar dealership’s service bay and ask about a dead AC unit, and they’ll quote you north of $1,200 for diagnosis and parts. Ask the same question on an RV forum, and someone will tell you it’s probably just a $35 capacitor. One of those answers leaves your wallet intact. The dealer isn’t wrong that AC failures are expensive—they’re wrong about *why* most of them happen. A Newmar Bay Star Sport’s rooftop Dometic unit fails more often from a burnt-out run capacitor or a stuck fan motor than from any major compressor breakdown, and catching it early means the difference between a thirty-minute fix and a five-figure rebuild. I’ve walked through dozens of these units during pre-purchase inspections, and a failed capacitor is the first thing I test for because it’s the most common culprit and the easiest to confirm. Let it slide, and you’re not just losing cold air—you’re watching the compressor work overtime until it dies completely, and suddenly that $30 part has cost you $1,500. This walkthrough covers exactly how to spot the problem and do the swap yourself, the same method I use before every resale showing, because a rig that keeps you cool on the road is also the one that actually sells.

The Run Capacitor That Stops the Fan Dead: Dometic 3312195.000 Replacement

A failed run capacitor is the silent killer of Dometic rooftop AC units—the compressor won’t start, the fan won’t turn, and you won’t know why until you’re staring at a $1,200 service call. This is the exact part that burns out on Bay Star Sports, usually somewhere between year 4 and 8, and it’s the first thing I pull when an AC unit is dead or running weak.

Parts and Tools

• Replacement run capacitor rated 60/5 MFD at the voltage specified on your original capacitor (typically 370V or 440V) — check current price
• Replacement fan motor assembly (Dometic 3312195.000 or equivalent) if the motor does not spin freely after capacitor replacement — check current price
• Needle-nose pliers or tweezers for disconnecting small spade terminals from the capacitor leads
• Multimeter set to capacitance mode (or ohms mode if capacitance unavailable) to test the old capacitor
• Insulated screwdriver set for removing the AC unit access panel and any terminal covers
• Electrical tape or heat shrink tubing to insulate reconnected spade terminals

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 labeled for the rooftop AC unit 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 control board. This prevents shock and protects the compressor from damage during the repair. Do not skip this step even if the unit appears dead.

Step 2: Access the capacitor inside the AC unit

Climb onto the roof using a ladder and safety harness. Locate the Dometic AC unit’s access panel on the side or bottom facing the interior of the rig. Remove the screws holding the panel in place and set them aside in a small container. Photograph the wire routing and terminal positions before disconnecting anything. The capacitor is usually a cylindrical component mounted vertically near the fan motor, with two or three spade terminals protruding from the top.

Step 3: Test the capacitor to confirm failure

Set your multimeter to capacitance mode and touch the probes to the two main terminals on the capacitor. A working 60 MFD capacitor should read between 55 and 65 MFD. If it reads zero, shows an open circuit, or the meter displays an error, the capacitor is dead. If you lack a capacitance meter, switch to ohms mode; a failed capacitor often shows infinite resistance. Document the voltage rating printed on the capacitor’s label before removal.

Step 4: Disconnect and remove the old capacitor

Using needle-nose pliers, gently pull each spade terminal off the capacitor leads. Take a photo of the terminal arrangement before removal to avoid confusion during reinstallation. If terminals are corroded or stuck, wiggle gently rather than yanking. Unscrew or unclip the capacitor mounting bracket and lift the component free. Do not discard it yet; you’ll need to verify the voltage and microfarad rating matches your replacement.

Step 5: Install the replacement capacitor

Verify the new capacitor matches the old one’s voltage (370V or 440V) and microfarad rating (60/5 MFD). Mount it in the same orientation and position using the original bracket. Reconnect the spade terminals in the exact order you documented in your photo. Push each terminal firmly onto its lead until it clicks or seats fully. Wrap each connection with electrical tape or slide heat shrink tubing over the joint to prevent accidental contact.

Step 6: Manually test the fan motor

Before closing the panel, gently spin the fan blade by hand. It should rotate freely without grinding, clicking, or resistance. If the blade is stuck or makes noise, the motor is likely seized and will need replacement. A stuck motor will burn out the new capacitor immediately. If the fan spins freely, proceed to reassembly.

Step 7: Reassemble and verify operation

Reinstall the access panel and tighten all screws. Climb down from the roof and return to the main panel. Flip the AC breaker back to ON. Set the thermostat to cool and listen for the compressor to start and the fan to spin. Feel the air coming from the vents after 30 seconds; it should be noticeably cooler than room temperature within two minutes. If the unit runs silently or produces no cold air, turn it off immediately and recheck your terminal connections.

What works

• Direct fit for Dometic units—no guessing on voltage or MFD rating, and the 60/5 dual-run spec matches the original OEM part exactly.
• Fan spins up instantly after installation and you hear the compressor kick in within seconds; the difference between a dead unit and one that actually cools is night and day.
• Costs about $35–$50 shipped, which means even if you’re wrong about the diagnosis, you’re not out mortgage money like you would be on a full motor or control board replacement.

What doesn’t

• Amazon’s stock on this specific Dometic part number is inconsistent—I’ve seen it take 2–3 weeks to ship, which is a problem if you’re full-timing and it’s 95 degrees outside.
• You have to be confident you’ve actually isolated a capacitor failure and not a seized motor or burnt control board; pulling the shroud and testing with a multimeter is non-negotiable or you’ll buy this part for nothing.

I once swapped a capacitor on a Bay Star Sport and the fan still wouldn’t turn, which made me question the whole diagnosis—until I realized the motor shaft itself was seized from years of dust buildup, and the new capacitor just wasn’t strong enough to force it. 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