No-start and hard-start diesel
No-start and hard-start diesel APU diagnostics
Truck-side troubleshooting for driver comfort systems
Mobile APU Repair
We diagnose the whole auxiliary power unit before selling a recharge. That means airflow, compressor command, condenser fan operation, battery voltage, control wiring, fuel delivery, and refrigerant charge are checked as a system.
- Refrigerants
- R-134a, R-404A, custom applications
- Brands
- Thermo King, Carrier, RigMaster, Dynasys
- Service
- Recharge, repair, leak checks, diagnostics
Service focus
APU repair
A sleeper that will not stay cool can lose freight time, rest time, and driver patience fast. Our mobile APU repair process is built for roadside lots, fleet yards, warehouses, distribution centers, and truck stops.
No-cool and weak-cool APU
No-cool and weak-cool APU air conditioning repair
Compressor, condenser fan, blower,
Compressor, condenser fan, blower, fuse, relay, and wiring checks
Battery, alternator, belt, sensor,
Battery, alternator, belt, sensor, fuel, glow plug, and control faults
Preventive maintenance after repair
Preventive maintenance after repair so the same failure does not repeat
Field process
How we approach APU repair
The goal is to identify the real fault, fix the cooling complaint, and avoid repeat downtime.
- Confirm the complaint We record vent temperature, battery voltage, APU run state, error behavior, and the exact conditions that make the failure show up.
- Test power and command We check fuses, relays, grounds, harnesses, controller signals, compressor clutch command, fans, and blower operation.
- Separate low charge from airflow faults Weak cooling is not automatically low freon. A clogged coil, failed fan, restricted drier, or oil-logged circuit can look similar.
- Repair with a clean exit test After the fix, the APU is run long enough to prove stable vent temperature, cycling, charging, and engine operation.
FAQ
Questions drivers ask before dispatch
Straight answers help avoid the wrong truck, wrong refrigerant, or wrong tool showing up.
Can you repair my APU at a truck stop?
Yes. Call dispatch with your unit brand, symptoms, and parking location. Mobile availability depends on the lane and tech schedule.
Do you service both diesel and electric APUs?
Yes. Diesel APUs, battery electric APUs, and custom sleeper cooling systems can be diagnosed by dispatching the right technician and equipment.
Is every no-cool APU just low freon?
No. Low refrigerant is common, but failed fans, dirty condenser coils, electrical faults, and restricted metering devices can cause the same driver complaint.