IllustrationTL* THE CONTACT OWNS A 2005 MONACO COACH DIPLOMAT. WHILE EXAMING THE VEHICLE, THE CONTACT NOTICED THAT THE TRANSFER SWITCH HAD BURNED. THE VEHICLE WAS TAKEN TO A LOCAL DEALER, WHERE THE SURGE PROTECTOR WAS REPLACED. THE FAILURE AND CURRENT MILEAGES WERE 33,000.
2005 Monaco Coach Diplomat
Owner reports · Recalls · Investigations
Limited comparison data
There is not enough comparable history to draw a useful model-year comparison.
About this comparison →How this year compares
Owner complaints by model year
Compare all Diplomat years →Counts vary with age, sales and reporting. They are not failure rates.
What owners reported most
Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
Limited mileage data: 1 of 1 reports include usable mileage. There isn’t enough coverage to show a useful chart.
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
- Electrical System. Review the 1 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
0 crash reports1 fire reports0 injury reports
Electrical System complaints
1 reportsOfficial recalls
204V598000 · Equipment:recreational Vehicle/trailer:lpg Systems:water Heater
Dec 23, 2004
ON CERTAIN MOTOR HOMES, THE WATER HEATER EXHAUST ON THE CURVE SIDE WALL UNDER THE BACK SIDE OF THE KITCHEN SLIDEOUT ROOM BOX TERMINATES UNDER THE SLIDE BOX WHEN IN THE EXTENDED POSITION. THIS DESIGN COULD CREATE A RISK OF MIGRATION OF CARBON MONOXIDE INTO THE INTERIOR OF THE MOTOR HOME.
Consequence & remedy
Consequence: EXPOSURE OF THE OCCUPANTS TO CARBON MONOXIDE COULD RESULT IN INJURY OR DEATH.
Remedy: DEALERS WILL REPLACE THE WATER HEATER WITH A 16 GALLON ATWOOD UNIT THAT HAS A DIFFERENT EXHAUST TERMINATION. THE RECALL BEGAN MARCH 25, 2005. OWNERS SHOULD CONTACT MONACO AT 1-800-685-6545.
04V441000 · Engine And Engine Cooling:engine:diesel
Sep 13, 2004
ON CERTAIN MOTORHOMES EQUIPPED WITH CUMMINS ENGINES, OIL CAN LEAK INTO THE ENGINE COMPARTMENT FROM A CRACK IN THE CUP PLUG.
Consequence & remedy
Consequence: OIL LEAKAGE ON A HOT ENGINE CAN RESULT IN AN ENGINE COMPARTMENT FIRE, POSSIBLY RESULTING IN INJURIES.
Remedy: CUMMINS IS CONDUCTING THE OWNER NOTIFICATION AND REMEDY FOR THIS CAMPAIGN. CUMMINS WILL INSTALL A STEEL CUP PLUG BOSS CAP TO ALL AFFECTED ENGINES. OWNERS SHOULD CONTACT CUMMINS CUSTOMER ASSISTANCE CENTER AT 1-800-343-7357 OR MONACO AT 1-800-685-6545.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0No exact-year investigations in this snapshot.