Recall 23V621 affects 679 2024 Thomas Built Buses Saf-T-Liner C2 buses for overheating AC electrical connections. Free repair at any franchised Thomas Built Buses dealer.
Thomas Built Buses is recalling 679 2024 Saf-T-Liner C2 school buses because the air conditioning electrical cables were not installed properly. The connection can overheat and increase the risk of a fire, and Thomas Built Buses dealers will complete the recall repair free of charge.
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What's wrong?
The A/C control module assembly on the 2024 Thomas Built Buses Saf-T-Liner C2 manages electrical power for the bus air conditioning system. Its cables carry current to the A/C components, and each connection needs to stay tight so power moves through the circuit without extra heat at the terminal.
In NHTSA campaign 23V621, some buses had A/C components installed outside the normal production process. That left some A/C electrical cables loose or improperly installed. A loose connection creates resistance, and resistance builds heat at the cable connection. If the connection overheats while the A/C is running, the driver overhead console area can overheat and the condition increases the risk of a vehicle fire.
The warning sign is an air conditioner that does not work or works intermittently. If the A/C cuts in and out, treat that as a service clue tied to this recall.
Who's affected?
| 2024 Thomas Built Buses Saf-T-Liner C2 | electrical system |
|---|---|
| Units affected | 679 |
| Field incidents | NHTSA has logged no field incidents to date. |
A matching year and model does not guarantee inclusion. Check your VIN to confirm whether your specific bus is included.
What's the safety risk?
An overheated electrical connection increases the risk of a fire. If the air conditioner stops working or works intermittently, treat that as a warning sign and schedule service soon. Keep using normal caution until your VIN is confirmed and the repair is completed. Repair is free at any franchised Thomas Built Buses dealer.
What should I do?
- Check your VIN to confirm your 2024 Thomas Built Buses Saf-T-Liner C2 is included in this recall.
- Contact a franchised Thomas Built Buses dealer to schedule the free AC electrical-cable inspection and tightening that fixes the overheating connection risk.
- Bring the recall notice if Thomas Built Buses mailed one. If not, reference recall number 23V621 when you call.
- Keep the bus out of service until the dealer completes the repair if you notice heat, smoke, or burning around the AC electrical connection.
What happens at the repair
At the dealer, a Thomas Built Buses technician inspects the air conditioning electrical cables and tightens the connections that need it. Parts and labor are covered under the recall, so the repair is free. If you've already paid out of pocket for this cable repair before the recall notice, seek reimbursement through an authorized dealer. Bring the owner letter, receipts, and repair paperwork so the service desk can match the prior work to recall 23V621.
| Reimbursement | Reimbursement available |
|---|
Timeline
| September 6, 2023 | NHTSA published the recall |
|---|---|
| October 19, 2023 | Owner notification mailed |
| November 5, 2023 | Dealer notification began |
| November 5, 2023 | Dealer notification ended |
| November 5, 2023 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 23V621?
Recall 23V621 covers 679 2024 Thomas Built Buses Saf-T-Liner C2 school buses with AC electrical cables that were installed improperly. The loose connection can overheat and increase fire risk. Thomas Built Buses dealers will inspect and tighten the electrical cables for free.
What should I do if my 2024 Thomas Built Buses Saf-T-Liner C2 is on this recall?
Check your VIN to confirm your specific bus is included in recall 23V621. If it is, contact a franchised Thomas Built Buses dealer to schedule the inspection and cable tightening. Reference recall 23V621 or DTNA recall number FL981 when you call. The repair is free.
Is the recall repair free?
Yes. Federal recall law requires manufacturers to repair safety defects at no cost. For recall 23V621, Thomas Built Buses dealers will inspect the AC electrical cables and tighten them as needed free of charge.
What is the safety risk?
The safety risk is fire. The AC electrical cable connection can overheat if the cables are not properly tightened. If your VIN is included, arrange the free dealer inspection and repair before continued service.
When were owners notified about this recall?
Owner notification letters were mailed October 19, 2023. If you did not receive a letter, check your VIN to confirm whether this specific 2024 Thomas Built Buses Saf-T-Liner C2 is included, then call a franchised dealer or DTNA customer service at 1-800-547-0712.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/23V621000 |
|---|---|
| Thomas Built Buses customer service | 1-800-547-0712 |
| NHTSA recall # | 23V621 |
| NHTSA recall # (full) | 23V621000 |
Source documents
-
Download Quarterly Report (PDF) - Download Owner Notification Letter (PDF)
- Download Owner Notice (PDF)
- Download Recall Report (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 20, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →