Land Rover Repair: S11 Land Rover Discovery A/C, coolant temperature sensor, land rover discovery

Question
flucuating air con fan speed on start up.
ie, when cabin hot instead of blasting away the fan speed goes high as it should then drops after a few seconds then up again and will keep this up for some time.

Answer
Hi Tony,

are we discussing a fault with the AC/Heater 'blower' motor or the cooling/condensor fan?  

IF it's the cooling fan it could be a coolant temperature sensor or the coolant thermostat.

IF it's the blower,  it could be a number of sensors involved with your DiscoII AC/Heater system, namely, in-car temp sensor, sunlight sensor, coolant temp sensor(mentioned above), ambient temp sensor , even the ATC ECU itself (dashboard control).  

It could be the blower relay or even the blower motor resistor.  It could also be the AC compressor itself that is failing.

You will need the help of someone who knows how to diagnose LR AC electrical problems - independent LR shop or (gag) LR Dealer.  Hopefully, it's a small problem (like a sensor) and not the ATC ECU itself.

Best of luck,
JohnMc