RoadVitals

2021 Thor Motor Coach Magnitude Problems

Owner-reported complaints filed with NHTSA, grouped by component

Data refreshed

Owner complaintsComplaints are reports submitted to NHTSA by owners and drivers. NHTSA does not verify most reports before publishing them, and a complaint does not establish that a defect exists. Volume is influenced by how many of a vehicle were sold, how long it has been on the road, and how much attention an issue has received.
3
Latest Sep 23, 2025
Components namedHow many of our component categories appear on at least one report for this model year. One report can name several.
3
Crash or fire reportedComplaints whose submitter recorded that a crash or a fire occurred. These are the reporter's own answers on the NHTSA form, not verified findings.
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What this page shows

Everything below is an owner-reported complaint submitted to NHTSA about the 2021 Thor Motor Coach Magnitude, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.

Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.

Reports by component

Ranked by how many owner reports name each component category

  • Electrical250.0%
  • Body & structure125.0%
  • Powertrain (other)125.0%

Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.

Each component in detail

What the reports in each category say, in the owners' own words

Electrical

Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.

2
reports

From owner reports, verbatim

Rear house battery tray weld failed, tray fell and hit the ground, damaging BIM, various cables etc. Identical to Recall 19V-566 (2019–2020) but not included for 2021.

Safety concern: Batteries may detach on roadway, cause shorts/fire, or total power loss.

NHTSA ID 11689266 · filed Sep 23, 2025

A wiring harness was found pinched, pins bent and broken, apparently in the process of mating the motorhome body to the cassis cab. This cable has power in it and could result in a vehicle fire. Thor has been completely unresponsive in assisting me, despite acknowledging it’s out of warranty, and I simply needed verification of their integration to the chassis, to reassure the after market warranty that this wasn’t something “tampered with”. As a retired fire fighter, I have seen the result of RV fires. They burn fast, and people die. I felt I had no option but to refer this after their intransigent and dismissive attitude. I can supply additional documentation when I retrieve the vehicle from the shop.

NHTSA ID 11527258 · filed Jun 15, 2023

Too few reports in this category for a page of its own — they appear in the full complaint list.

Body & structure

Reports naming the vehicle structure, frame, body panels, doors, hood and trim.

1
report

From owner reports, verbatim

Rear house battery tray weld failed, tray fell and hit the ground, damaging BIM, various cables etc. Identical to Recall 19V-566 (2019–2020) but not included for 2021.

Safety concern: Batteries may detach on roadway, cause shorts/fire, or total power loss.

NHTSA ID 11689266 · filed Sep 23, 2025

Too few reports in this category for a page of its own — they appear in the full complaint list.

Powertrain (other)

Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.

1
report

From owner reports, verbatim

TL* THE CONTACT OWNS A 2021 THOR MAGNITUDE BB35 BUILT ON A 2020 FORD F-550 CHASSIS N/A. THE CONTACT STATED WHILE STATIONARY AT A TRAFFIC LIGHT, WHILE THE DEPRESSING THE ACCELERATOR PEDAL, THE RV MADE AN ABNORMAL NOISE AND STARTED TO ROLL BACKWARDS. THE CONTACT STATED NO WARNING LIGHT WAS ILLUMINATED. THE CONTACT STOPPED THE RV BY DEPRESSING THE BRAKE PEDAL. WHILE SHIFTING TO PARK, THE RV CONTINUED TO ROLL BACKWARDS. THE CONTACT STATED HE USED THE PARKING BRAKES TO KEEP THE RV FROM MOVING. THE RV WAS TAKEN TO WAY SCARFF FORD COMMERCIAL TRUCKS (119 7TH ST NE, AUBURN, WA 98002: (888) 394-6998) WHERE IT WAS DIAGNOSED WITH NEEDING THE DRIVE SHAFT TO BE REPLACED. THE VEHICLE HAD NOT BEEN REPAIRED AS OF YET. THE MANUFACTURER HAD BEEN INFORMED OF FAILURE. THE FAILURE MILEAGE WAS 6,671.

NHTSA ID 11384080 · filed Dec 18, 2020

Too few reports in this category for a page of its own — they appear in the full complaint list.

Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.

Elsewhere on this vehicle

Data sources

Data on this page last refreshed .