IllustrationDEFROSTER NOT WORKING WINDSHIELDD ICED OVER WHEN DRIVING FROM SNOW. WHEN STOPED DEFROSTER WILL OUTPUT ENOUGH HEAT TO MELT ICE. HEATER DEFROSTER IS SUB STANDARD INSUFFICIENT HOT WATER FLOW FROM REAR MOUNTED DIESEL ENGINE TO HEATER CORE ABOUT 37FT.
2004 Monaco Coach Diplomat
Owner reports · Recalls · Investigations
Limited comparison data
There is not enough comparable history to draw a useful model-year comparison.
Counts are not adjusted for sales, age, mileage exposure or reporting. A lower count does not establish that a car is problem-free.
About this comparison →4Owner complaints
Model-year median: 2
1Recall campaignsView recall details →
0InvestigationsView investigation details →
Check a VIN with NHTSA ↗ Model-level counts do not show whether a particular VIN is affected or repaired.
Inspection summary
2004 Monaco Coach Diplomat
NHTSA snapshot: September 18, 2026. 4 owner complaints · 1 recall campaigns · 0 investigations.
Counts are not failure probabilities and are not adjusted for sales, age, mileage exposure or reporting. One report may name several categories. Comparison method and limitations.
Top reported categories (up to 5)
- Electrical System: 2 reports
- Service Brakes, Hydraulic: 2 reports
- Structure: 2 reports
- Visibility: 2 reports
- Equipment: 1 reports
Full reported-category list and vehicle report
Recall links
Check a VIN with NHTSA. Model-level history does not establish whether a particular VIN is affected or repaired.
Print the top reported categories, recall links, snapshot date and comparison limits.
How this year compares
Owner complaints by model year
Compare all Diplomat years →Counts vary with age, sales, mileage exposure and reporting. They are not failure rates.
What owners reported most
All reported categories
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: 3 of 4 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 2 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Service Brakes, Hydraulic. Review the 2 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Structure. Review the 2 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 reports0 fire reports0 injury reports
Visibility complaints
2 reportsDEFROSTER NOT WORKING WINDSHIELD ICED OVER WHEN DRIVING FROM SNOW AND FREEZING RAIN.WHEN STOPED DEFROSTER WILL OUTPUT ENOUGH HEAT TO MELT ICE. HEATER DEFROSTER IS SUB STANDARD.
Recall campaigns
104V441000 · 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 ↗
Defect investigations
0No exact-year investigations in this snapshot.
An investigation is not a finding of a defect, and closure does not prove a vehicle is problem-free.