2009 MONACO SIGNATURE SERIES FORTRESS IV
Description
2009 Monaco Signature Fortress IV Class A Diesel Motorhome
One Owner | Cummins ISX 650 | Less Than 500 Miles on Replacement Engine | Extensive Upgrades | Complete Service History
This 2009 Monaco Signature Fortress IV is an exceptional one-owner luxury diesel motorhome with a complete service history from new and extensive recent mechanical upgrades.
Most notably, Cummins installed a replacement ISX 650 HP diesel engine in 2023, and the engine has less than 500 miles on it. The coach has also received major chassis, drivetrain, electrical, and suspension updates, making it an outstanding example of Monaco’s flagship Signature line.
Major Mechanical Upgrades
The owner has invested heavily in keeping this coach mechanically current and road-ready.
Recent work and upgrades include:
Cummins-built ISX 650 HP replacement engine installed in 2023
Less than 500 miles on the replacement engine
Transmission rebuilt in 2020
All airbags and shocks replaced in 2022
Complete coolant hose replacement in 2023, including generator hoses
Radiator flushed and coolant pump rebuilt
Engine bay hoses and connections inspected prior to engine installation
Magnum inverter replaced in 2023
Battle Born lithium-ion house batteries installed in 2023
Steering stabilizer system
Dual air and hydraulic leveling systems
Brand-new spare drive shaft stored onboard
The replacement Cummins engine was originally covered by warranty through October 2025.
Complete One-Owner Service History
This Monaco has been owned by the same owner since new and comes with comprehensive maintenance and service records.
The detailed history provides valuable insight into the coach’s care, repairs, and upgrades over the years, with records available for review.
Luxury Monaco Signature Interior
Inside, the Signature delivers the high-end craftsmanship and residential comfort Monaco was known for.
Interior highlights include:
Handcrafted polished wood cabinetry
Premium leather seating
Residential refrigerator
Convection microwave
Induction cooktop
Dishwasher
King-size bed
Washer/dryer
Heated residential-style flooring
Elegant bath and shower area
Multiple flat-screen televisions
Bose surround sound system
Both the driver and passenger ride in premium Knoedler air-cushion captain’s chairs featuring heat, air conditioning, and massage functions.
Technology & Exterior Upgrades
This coach has also received several valuable custom upgrades designed to improve visibility, convenience, and long-distance travel.
Features include:
Custom four-camera exterior camera system with large-screen monitor
Navigation system
Wi-Fi extender
Keyless entry
Full front cap protected by Paint Protection Film
Power-operated storage bay slides
Newly carpeted storage compartments
LED rope lighting around the entire underside perimeter
30-amp outlet in storage bay for stacker trailer use
Tow hitch with air line for trailer braking system
Separate rear driver-side hitch for flagpole
Power, Water & Comfort Systems
The coach is equipped for extended travel and comfortable year-round use with:
Onan 12.5kW diesel generator
Oasis hydronic heating and hot water system
Custom reverse osmosis water filtration system
Dual-zone climate control
150-gallon diesel fuel tank
100-gallon fresh water capacity
Why This Monaco Signature Stands Out
It is increasingly difficult to find a flagship luxury diesel coach with this combination of one-owner history, complete service documentation, and extensive recent mechanical investment.
With its 650 HP replacement Cummins engine, rebuilt transmission, updated suspension, lithium battery system, premium interior, and numerous custom upgrades, this Monaco Signature Fortress IV offers tremendous value for a buyer looking for a high-end diesel motorhome that has been exceptionally well cared for.
Contact Cassones RV today to schedule a private showing and see this remarkable 2009 Monaco Signature Fortress IV in person.Specifications
Stock Number335C
VIN1RF17561091049437
Year2009
Mileage171,768 mi
ManufacturerMONACO
ModelSIGNATURE SERIES FORTRESS IV
RoadworthyYes
LocationMesa, Arizona 85213
ConditionUsed
Fresh Water Tank Capacity100 gal
Gray Water Tank Capacity72 gal
Black Water Tank Capacity40 gal
Sleeps2
Number of Slide Outs4
GeneratorYes
Number of Rear AxlesTandem
Exterior Length44 ft 11 in
Exterior Width8 ft 5 in
Exterior Height12 ft 8 in
Drive SideLeft Hand Drive
Air ConditioningYes
Horsepower650 HP
Engine ManufacturerCUMMINS
Engine ModelISX
Stock Number335C|
VIN1RF17561091049437|
Year2009|
Mileage171,768 mi|
ManufacturerMONACO|
ModelSIGNATURE SERIES FORTRESS IV|
RoadworthyYes|
LocationMesa, Arizona 85213|
ConditionUsed|
Fresh Water Tank Capacity100 gal|
Gray Water Tank Capacity72 gal|
Black Water Tank Capacity40 gal|
Sleeps2|
Number of Slide Outs4|
GeneratorYes|
Number of Rear AxlesTandem|
Exterior Length44 ft 11 in|
Exterior Width8 ft 5 in|
Exterior Height12 ft 8 in|
Drive SideLeft Hand Drive|
Air ConditioningYes|
Horsepower650 HP|
Engine ManufacturerCUMMINS|
Engine ModelISX|
