On‑Site Mobile Diesel Fleet Technician

W.W.Williams; Tucson (AZ); On-site; USD 60,000 - 80,000; Full time

Benefits offered by this job

8 Paid Holidays

Paid time off

Employee Referral Bonus Program

Medical, Dental, and Vision Insurance

401k with a Company Match

Company Paid Training

Growth and Leadership Opportunities

Job summary

W.W. Williams is seeking a Mobile Fleet Technician to perform on-site preventive maintenance, inspections, and diagnostics on diesel engines and heavy-duty trucks at customer sites around Tucson.

You will work independently, ensure DOT compliance, and deliver high-quality repairs. The role emphasizes strong diagnostic skills, familiarity with A/C, emissions, and electrical systems, plus the ability to plan repairs, manage parts, and document work accurately.

Qualifications

• 3+ years of diesel repair experience; 5–7 years preferred in fleet, dealership, or mobile technician environments.
• Certificate from a technical school or equivalent hands-on experience.
• Valid Driver's License and DOT Medical Card (or ability to obtain).
• ASE Certifications: T4 (Brakes), T7 (HVAC), T8 (PM).
• MACS 609 or equivalent mobile A/C certification.
• Strong diagnostic and troubleshooting skills across multiple systems (brake, emissions, electrical, HVAC).
• Familiarity with repair planning and parts reuse.
• Proficient in Microsoft Office and diagnostic software.
• Clear written and verbal communication.
• Ability to work in physically demanding environments.

Responsibilities

• Perform quality repairs and preventive maintenance on diesel engines and heavy-duty trucks per manufacturer specifications.
• Conduct thorough vehicle inspections to identify damaged, worn, or broken parts.
• Create and execute job repair plans based on diagnostics, including estimating labor hours and required parts.
• Diagnose and repair electrical systems, A/C systems, emissions controls, and other diesel engine components.
• Complete PM services, DOT inspections, and documentation accurately and thoroughly.
• Use diagnostic software and follow electronic repair procedures.
• Maintain a clean and safe work area, both on customer sites and in the company vehicle
• Maintain accurate records for invoicing and warranty claims.
• Utilize company tools appropriately and maintain a personal tool inventory per company policy.
• Support and train junior technicians as needed.
• Adhere to all safety, EPA, and company policies.

Skills

Diesel repair experience

Diagnostic and troubleshooting skills

Independent work

Clear communication

Physical stamina

Customer-focused mindset

Education

Technical school certificate or equivalent hands-on training

DOT Medical Card or ability to obtain

Valid Driver's License

Tools

Diagnostic software

Microsoft Office

ASE T4/T7/T8

MACS 609

Job description

W.W. Williams is seeking a Mobile Fleet Technician to perform on-site preventive maintenance, inspections, and diagnostics on diesel engines and heavy-duty trucks at customer sites around Tucson.

You will work independently, ensure DOT compliance, and deliver high-quality repairs. The role emphasizes strong diagnostic skills, familiarity with A/C, emissions, and electrical systems, plus the ability to plan repairs, manage parts, and document work accurately.