Since I’m hunting EAS issues I came up with this simple off vehickle tester for P38 EAS pressure switch.

What you need is an mountain bike Suspention air pump and an adapter NPT to Schrader valve
  I used what I had in my box and came up with what yo see in the pictures but if I would have started from scratch I had bought a NPT-NPT adapter and a shrader with the same thred.
You also need a test device like a multimeter or even better a bulb and a power source (Since it put some load on the pressure switch cointacts).

This is how it looks, nothing fancy quite straigt forward.

Demo of funktional test of Range Rover P38 EAS (Electronic Air Suspension) pressure switch.

Simple testrig using a hand pump that are quite common as used for MTB suspension, this sample is capable of 300psi so more than enough for this task. Test connectors can be whatever you find suitable, it’s only 2 wires that are neded and yoy gan easily trace them by eye, i used some narrow generic flat contacts comonly used on …. most thisngs in old vihecles :D

Pump andad apter connected to pressureswitch switch should be closed at about 150psi and open arround 110 (Not super critical).

I happened to have a schrader valve tap to I improviced this adapter  Link to parts ;)