Parking AC Wiring Diagram: 12V and 24V Connection Reference

• Table of Contents

1. Block diagram (12V version)
2. Block diagram (24V version)
3. Cable and fuse summary
4. Request the full PDF schematic

This page is the wiring reference for installers — block-diagram description of the Vethy parking AC, sleeper bank, isolator and ground bond, with cable and fuse spec for both 12V and 24V versions. The full PDF schematic is shipped with each unit and available on request.

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.

Block diagram (12V version)

Cranking battery (12V) → smart isolator → sleeper bank 4×100 Ah AGM (12V) → 40 A blade fuse → 6 AWG positive → Vethy parking AC unit + input. Unit – input → 6 AWG negative → chassis ground point (or back to sleeper bank – terminal).

Alternator charges cranking battery directly. Isolator passes charge to sleeper bank only when cranking battery is >13.4 V (engine running). At engine off, isolator disconnects to protect cranking capacity.

Block diagram (24V version)

Cranking battery (24V, 2×12V series) → smart isolator / DC-DC charger → sleeper bank 2×100 Ah AGM series (24V) → 25 A blade fuse → 8 AWG positive → Vethy parking AC unit + input. Unit – input → 8 AWG negative → chassis ground point.

Cable and fuse summary

Request the full PDF schematic

Email info@vethy.com with your model number for the model-specific PDF schematic and harness drawing.

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

Is the schematic public?

The block-level wiring spec is public (this page). Detailed PCB-level schematics are shared with OEM partners under NDA.

Does the unit need a neutral or just two wires?

Just two wires: positive (fused) and negative (chassis ground). No separate neutral needed for DC.

Can I use the same harness on 12V and 24V units?

Cable gauge differs (6 AWG vs 8 AWG) and fuse differs (40 A vs 25 A). Use the harness shipped with the specific unit.

Where does the remote control wire?

Vethy remotes are wireless (RF). No control wiring needed between the unit and the remote.