Published 15 November 2026 · OFM4x4.co.uk

An air locker installation combines electrical switching with an air circuit and differential hardware. A compressor starting does not prove that the locker is correctly engaged.

The quick answer

Use the locker and compressor manufacturer's wiring and operating instructions for the exact kit. Have the installation checked before use on an appropriate surface.


Identify the components

Record the locker model, compressor, pressure switch, solenoids and switch harness. Similar switches can have different connector pinouts. Do not splice a circuit by wire colour alone.


Follow the designed interlocks

The intended front and rear switch logic varies by kit. Check illumination, fuse placement and any controller requirements against the current diagram. A bypass can create an unexpected engagement state.


Check air operation

Listen for repeated cycling, inspect fittings and follow the maker's pressure test procedure. Air leakage, electrical supply and differential installation are separate fault paths.


Operate responsibly

Engage only as the manufacturer's guide allows, taking account of surface and vehicle movement. Disengage and verify normal behaviour after leaving the obstacle. Stop if steering or driveline behaviour is abnormal.


Specification checklist

Before ordering or booking work, have these details ready: Locker and compressor model codes, harness diagram, switch position and fault symptoms.


Frequently asked questions

Can I use any compressor switch with an air locker?

Only if the electrical and air control arrangement is approved for the specific system.

For an application check, contact OFM4x4.co.uk with the vehicle and component details above. Confirm the current fitting instructions for the exact product before work starts.

Technical reference: www.arb.com.au. The relevant product manual takes priority over general guidance.