24V Parking AC Wiring: EU Heavy Truck Install Guide
Wire a 24V Vethy parking AC into a DAF, Volvo, Scania, MAN or Mercedes Actros sleeper bank.
May 19, 2026
Table of Contents
EU heavy trucks run a 24V chassis. A Vethy 24V parking AC draws about 18 A on startup and 9 A in night-mode cooling — half the current of the 12V version at the same wattage. This page covers the wiring spec for a clean install on DAF, Volvo, Scania, MAN, Mercedes Actros and similar 24V heavy trucks.
This page is a generic field troubleshooting guide for Vethy 12V/24V parking air conditioners. Always disconnect the battery before opening the unit and follow the install manual that shipped with your specific model. Refrigerant work (R410A) must be performed by a certified technician.
Cable, fuse and connector spec
- Cable: 8 AWG (10 mm²) tinned copper, both positive and negative, for runs up to 4 m.
- Fuse: 25 A blade fuse on positive, within 30 cm of the battery terminal.
- Connector: M8 ring at battery, Anderson SB50 at unit.
- Ground: dedicated chassis ground point, clean bare metal + anti-corrosion coat.
24V sleeper bank topology
Most EU heavy trucks have 2×12V batteries wired in series for the 24V chassis. For parking AC use, add a dedicated 24V sleeper bank: 2×100 Ah AGM in series (200 Ah total at 24V), isolated from the cranking circuit by a Sterling / CTEK / factory smart isolator.
Low-voltage cutoff for 24V
Vethy 24V units cut off at 22.8 V (≈11.4 V per cell). This protects cranking capacity on 2×12V series banks. Do not disable.
EU CANbus considerations
The parking AC runs on a fused battery feed — independent of the CANbus. Optional CAN telemetry is available for fleet integration on OEM contracts. See OEM/ODM scope.
If the problem persists after the steps above, contact Vethy support with the unit serial number, install year and a short video of the symptom: info@vethy.com · Open a support ticket.
Frequently asked questions
Can I use a 12V Vethy AC on a 24V truck with a converter?
Not recommended. Converters add 10–15 % loss and reliability risk. Use the native 24V variant.
Will the EU smart alternator charge a dedicated sleeper bank?
Yes via a B2B isolator (Sterling, CTEK D250). EU smart alternators with variable voltage need a DC-DC charger, not a simple split relay.
Is the 24V install dealer-friendly?
Yes. Typical install on a DAF XF or Volvo FH takes 4 to 5 hours including roof prep and wiring.
Do you ship a complete harness?
Yes — 4 m harness with fuse, ring terminals and Anderson connector is included in the 24V box.
Ready to spec a Vethy parking AC?
Quote requests, OEM enquiries and distributor applications are handled by the same team. Typical response time is 2 to 5 working days.
→ Request a quote | Email info@vethy.com | WhatsApp +86-153-1425-2983