Greetings from Nepal! I run a small workshop here, not a lot of experience with euro cars. We get mostly asian makes.
I need some assistance with a 2008 rangerover tdv8.
The ac condenser fan runs at full speed when the vehicle starts.
We replaced the old one since it was not coming on when the ac was switched on .
The fan has three wires going to it .
A constant +ve , a constant -ve. And a thin wire which I think is the control wire.
When I switch the ignition on the fan doesn't come on , but if I ground the control wire with a test light it switches on .
I tried disconnecting the HVAC control unit in the vehicle, but still the fan comes on .
The ambient temp, engine temp , are all within spec.
Bi -ditectional activation of the fan speed is possible when the key is on the on position .
Any help would be greatly appreciated.
Thank you !.

Some scantool data .
The ac compressor relay is on the on state. Even when the ac switch is not switched on .
The ac compressor clutch state does come on when switch is pressed and goes off when it's not pressed.

Have you tried another relay?
Are there any DTCs stored in the PCM?

No fan relay for the same engine and radiator group in the RRS either, so the PCM has to be controlling it.

Have you checked for DTCs in the PCM? Presumably a battery disconnect has been tried.

No dtcs stored.
Yes a battery disconnect has been tried aswell with no luck .

Maybe not helpful, but I'm reminded of a very early (1st batch 1999) TD5 D2 that I owned that ran the cooling fan constantly with the ignition switched on if the coolant temperature sensor signal had been invalid (the sensor had been disconnected). The fault wouldn't clear so a new ECM had to be fitted.

Do you have access to a different scan tool in case it can find another DTC? If your tool is an IIDtool then have you set it to show all faults, as the devices are distributed with 1 required option unchecked (pending faults IIRC).

Thank you for the suggestion. I will try and get hold of another scantool.iam using a launch x431 at the moment.

Have you tried changing the Final Stage Resistor (FSR)... a common fault which effects the fan...

Youtube has videos on doing it, not a bad job...

If you plan on keeping the car buy genuine...  Pete

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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

I have a new fsr and will try that tomorrow.
I thought it only affects the blower motor though .

Sorry, misread the first post....  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-