Advertise on fullfatrr.com »

Home > Technical (L322) > Curious AC fault
Post Reply  Down to end
Page 1 of 1
Print this entire topic · 
Thunderbird2



Member Since: 06 May 2021
Location: Sydney NSW
Posts: 7

Australia 2007 Range Rover Vogue TDV8 Buckingham Blue
Curious AC fault

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


My working hypothesis is "something funky and electrical", since the normal operation followed by a staged shutdown seems stranger than what you might expect from a component which has just straight up failed. Partial failure of a blower motor? Resistor pack?

All input welcome.

Thanks all

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

Post #602650 3rd Aug 2021 10:08am
View user's profile Send private message View poster's gallery Reply with quote
DrRob



Member Since: 16 Apr 2015
Location: Petersfield, Hampshire
Posts: 4302

United Kingdom 2011 Range Rover Vogue SE TDV8 Buckingham Blue

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.
Thumbs Up 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
--------------------------------------------------

Post #602652 3rd Aug 2021 10:15am
View user's profile Send private message View poster's gallery Reply with quote
mjdronfield



Member Since: 04 Nov 2011
Location: Derbyshire
Posts: 7799

United Kingdom 2011 Range Rover Vogue SE TDV8 Buckingham Blue

+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.

Thumbs Up 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

Post #602665 3rd Aug 2021 12:44pm
View user's profile Send private message View poster's gallery Reply with quote
Thunderbird2



Member Since: 06 May 2021
Location: Sydney NSW
Posts: 7

Australia 2007 Range Rover Vogue TDV8 Buckingham Blue

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)

Post #602768 4th Aug 2021 8:54am
View user's profile Send private message View poster's gallery Reply with quote
Merchy



Member Since: 14 Feb 2021
Location: North Wales
Posts: 1183

United Kingdom 2006 Range Rover Vogue Td6 Zermatt Silver

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

Post #602789 4th Aug 2021 10:52am
View user's profile Send private message View poster's gallery Reply with quote
Thunderbird2



Member Since: 06 May 2021
Location: Sydney NSW
Posts: 7

Australia 2007 Range Rover Vogue TDV8 Buckingham Blue

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 Rolling Eyes . 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)

Post #605377 1st Sep 2021 11:57pm
View user's profile Send private message View poster's gallery Reply with quote
Haylands



Member Since: 04 Mar 2014
Location: East Yorkshire
Posts: 8207

England 2014 Range Rover Autobiography SDV8 Loire Blue

Cool... Very Happy 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-

Post #605380 2nd Sep 2021 7:25am
View user's profile Send private message View poster's gallery Post Reply
Post Reply  Back to top
Page 1 of 1
All times are GMT

Jump to  
Previous Topic | Next Topic >
Posting Rules
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum



Site Copyright © 2006-2024 Futuranet Ltd & Martin Lewis
fullfatrr.com RSS Feed - All Forums


Switch to Mobile site