Hi all

After years of wanting, I have taken the plunge into FFRR ownership. Managed to pick up a very tidy '07 3.6 Vogue which has enjoyed transmission oil changes every 60,000km (37k miles) and a brand new engine 70,000km ago.

She's been pampered her whole life..... buuuuuut, it's a Range Rover, and there's no way I'd get away with faultless performance!

I've noticed an issue with the air conditioning. I have read the forums here and on other sites, but can't find anything which quite matches my symptoms.

I do not fully understand the AC's principles of operation, so I'd appreciate suggestions as to the root cause, as well as to what other tests I should carry out to narrow down the possibilities.

THE FAULT: Around 4 minutes after start up, the blower will begin to cycle between 'off' and the original blower speed. It will continue to cycle, with the 'higher' fan speed getting lower and lower each cycle until the blower simply stays off.

OTHER OBSERVATIONS:

- The air con will operate normally from start up, and respond correctly to all user inputs across a full temperature range during this time. Adjusting the temperature while in 'Auto' produces the expected changes in blower speed
- The 'MAX' function works fine
- The air produced by the system is nice and cold
- Each on/off cycle takes about 2 seconds
- The rear AC panel works fine and its operation does not appear to impact or being impacted by the fault in the front
- The fault presents itself irrespective of whether the engine is hot or cold
- The fault clears when the engine is shut down and the key removed: restarting (even within a few minutes) appears to clear the fault

I'd start with changing the Final Stage Resistor (aka Hedgehog) for a new one. Don't buy a cheap one.
Easy to swap out iirc on majority of cars.
 Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
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+1 for the above. They do fail from time to time and would be my first port of call. Tends to cause erratic blower speeds..... would it cause all the symptoms you have... not sure, but I would definitely remove it from the equation first.

 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

Thanks guys, looks like I'm going hedgehog shopping.

Will update this thread with results. 2007 FFRR Vogue 3.6 TDV8 (Buckingham Blue)
1979 Jaguar XJ12 5.3 LWB (Juniper Green)

Noted, yours is a 2007, so hope this may help, see the below for changing the hedgehog. Not a huge job, just a pain working in the foot well.

https://www.rswsolutions.com/index.php/mki...e-resistor

Hi everyone

By way of update, changing out the FSR seems to have cured the fault.

While I was in there I found the original FSR still in place but disconnected, and a second FSR wired in but hanging from the steering column by a cable tie . Both were genuine parts, made in Germany: makes me wonder if the second failed because it overheated, being outside the AC duct, or whether the blower motor is on the fritz and is killing FSRs.

Oh well- time will tell! The new one is installed (properly) in time for the Australian summer.

Merchy- that link was a great help. As you say, not complex, just a little fiddly. Having worked on 70s and 80s Jags, I'm used to sticking my hand in confined spaces, closing my eyes, and letting my fingers figure out what's going on!

Have a great one, all

Will 2007 FFRR Vogue 3.6 TDV8 (Buckingham Blue)
1979 Jaguar XJ12 5.3 LWB (Juniper Green)

Cool...  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
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