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2006-2009 Range Rover MkIII / L322
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Discussion Starter #1
I drove 30 minutes to a park, went for an hour walk, andwhile my A/C has been blowing cold for years, it suddenly was blowing nothing but completely un-cooled outside air. I thought maybe the exchanger had iced up, but I just tried it again after letting it sit for 4+ hours. I think it’s electrical... Any ideas?
 

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2006-2009 Range Rover MkIII / L322
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Is your radiator fan spinning? If your electric clutch has failed that will cause the system to just blow outside air temp from the vents in no time, you should be able to hear the fan blowing air just by listening. My clutch just failed and mine won't blow any cool air at the moment, just air about 5 degrees less than the outside temperature. Is the compressor clutch engaging? Just look down at the front of the compressor and make sure the clutch is engaged, and the center hub is spinning with the outer belt pully Is the A/C line over the top of the fan shroud warm (or HOT), and the one along the left side of the engine cool or cold?
 

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2006-2009 Range Rover MkIII / L322
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Discussion Starter #3
The radiator fan is spinning, but with the shrouding all in-place, I can’t even see the belt... I still think it is electrical. Here’s why: sometimes some weird electrical gremlin makes my turn signals not work, and lowers the electric steering wheel to a hilariously low point. It’s basically rubbing my legs and I feel like I’m driving a go cart. If I remove one of the contacts from the battery for a little bit, it seems to reset.I had to do that before coming home from the park yesterday, and it was after that that the AC was suddenly not working.
 

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When this happened to my 2003 RR, I replaced the Final Stage Resistor. easy job. Has been fine ever since. Hope it helps.
 

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2006-2009 Range Rover MkIII / L322
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Discussion Starter #5
So, I took it to the general mechanic shop yesterday and they told me this morning it needs new everything... $1750. Ugh. That just can't be right, unless something major happened to it while it sat in the parking lot. How did you know / how would I know if it was the Final Stage Resistor? An easy fix for $31.92 sounds waaaay better than $1750. Thanks a ton -
 

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2010-2012 Range Rover MkIII / L322
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Is the HVAC fan blower working (even if it’s blowing ambient temperature air)?

Do the HVAC controls divert the air from each selected vent outlet?

If so, it’s worth having a specialist ac shop evacuate, vacuum test and refill the ac with R134a to the correct spec (fill label on the front panel).

The vehicle may just need to be refilled.

Rob
 

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2006-2009 Range Rover MkIII / L322
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Final Stage Resistor affects the inside fan only, if air of any temperature is blowing out of the vents and you can speed the fan up and down from the HVAC controller on the dash its not the FSR.
 

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2006-2009 Range Rover MkIII / L322
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Discussion Starter #8
Ok, well that's all good to know. I did replace the FSR but it didn't seem to change a thing. I can speed the fan up and down.

I did take it out for a drive just now (after the FSR change-out), and it was not blowing cold at first, then I turned the A/C off for 20 minutes, then I turned it on and - eureka! - it was blowing cold air! For about 4 minutes, then it started to get warm again. Any thoughts? Please tell me it's just low of refrigerant...
 

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2006-2009 Range Rover MkIII / L322
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Discussion Starter #10 (Edited)
Is the HVAC fan blower working (even if it’s blowing ambient temperature air)?
Yes, it’s blowing and the fan speed is controllable.

Do the HVAC controls divert the air from each selected vent outlet?
I’m not sure about this one... Are you referring to the three people icons, one blowing up (towards the windscreen?), one blowing out to the passengers, and one blowing towards you feet? In any event, I can’t really tell.

If so, it’s worth having a specialist ac shop evacuate, vacuum test and refill the ac with R134a to the correct spec (fill label on the front panel).
Ok, that I can do, but does the fact that it’s working intermittently suggest anything to you? The guy at the shop says they tried to run power straight to the compressor and it didn’t do anything. Could it be the compressor / condenser / whatever clutch?

Is there any chance it's a battery issue? I've had some weird electrical gremlins acting up on the thing, and that definitely happened the day it suddenly quit.
 

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2010-2012 Range Rover MkIII / L322
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Perhaps I wasn’t as clear as intended; by “checking the vents” I meant “does the HVAC system blow at least ambient air to the windshield vents and or foot wells when selected?”

You might consider finding a reliable local vehicle AC specialist who can connect their shop equipment to determine how much existing R134a gas can be pulled from the AC system (as measured by weight). If it’s less than the amount on the yellow AC fill label on your radiator support - 750g for two zone, 950g for four zone - the system may just be low on gas.

Ask them to then draw, and maintain, a deep vacuum in the AC system for at least 45 mins to check for system leaks (they’ll know what you mean).

If the system maintains a deep vacuum for greater than 45 minutes have them fill the AC system with the correct amount of R134a - per the yellow fill label.

They should then check the HI and LO pressures with HVAC gauges to determine the efficiency of the AC compressor.

It’s entirely possible that the compressor is less than perfect but as a rule, they’re pretty reliable. Certainly not a known weakness to date.

Replacement compressors are in the $300 range for the part. As a rule, replace the drier (desiccant) too when replacing a compressor.

Rob
 

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My compressor ate it recently, although my truck does have 210K miles on it, it just wasn't putting out much cold air, probably no colder than 60-65 degrees, driver side was colder than passenger side as is typical with low refrigerant, didn't matter if it was driven on the highway or on side streets, ie it wasn't rpm based where it got colder at lower speeds and hotter on the highway. Low pressure side was at about 45 to 60 psi, and the high side was only about 150 psi and both the return and discharge lines from the compressor were almost the same temperature, normally the discharge line is HOT (like burn your arm hot if you lean on it) and the return line to the compressor is probably 50 degrees. The high return and low discharge pressures is either a sign of a compressor problem or that the TCV valve is stuck open, pressures should normally be somewhere in the 30-40 psi low side, and 250-300 psi high side depending on outside air temperatures.

I pulled the cover off the TCV box, and the line was warm on one side and cool on the other, so I figure it was at least doing something. So I added some refrigerant figuring it was low, no difference in either pressures or temperatures, then I drained all the refrigerant out, drew a vacuum for 2 hours (left the pump riunning), held it for about another hour then recharged the proper amount of refrigerant (700 g in my case), it made no difference.

So I replaced the compressor. Its a bit of a pain in the butt to do but since I was changing belts and the alternator at the same time I was most of the way there. The engineers that designed the bracketry and mounts for stuff on the 4.4L should all be made to work on them for months straight with no sleep or breaks. The compressor has a bracket behind it that holds the aux (main? anyway the back one) belt tensioner, that bracket has two bolts that bolt directly to the block, and the compressor has 3 longish bolts that pass thru all the way thru that bracket and also bolt to the block. Two of those bolts can be removed from holes thru the compressor once they are loose, the third one can't be removed as it hits the front fender support, so you have to wiggle the compressor out away from the bracket, reach behind it and remove the two bolts that hold the bracket to the block so you can pull that out to get clearance to move the compressor to get the last bolt out so you can wiggle that out from next to the engine. Anyway, replaced it recharged it again and now the air coming out the center vent is 40 degrees so apparently my compressor had just worn out over time, and I didn't realize it this year until it started getting hot out.

Take it to an A/C place and at least get them to diagnose it, parts are expensive, much more than a diagnostic fee.
 

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1995-2002 Range Rover P38A
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I replaced the compressor on my 2008 full size supercharged last year and I agree it is a pain. Taking the belt tensioner completely off helps quite a bit. In my case the shear bolts between the clutch and the drive plate failed so there was no longer a connection even with the clutch engaged. Compressor was about $300 from Rock Auto. I also had some trouble getting the hoses to seat properly on the compressor so I was kind of expecting a leak but this summer all is cool:). I took the old compressor completely apart and could find nothing wrong with it. No idea why the shear bolts failed. There is a post on my experience.

I don't think this should cost anything like $1,750 to fix.
 

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Discussion Starter #14
Thanks all. I’m at the independent Land Rover shop this AM and it seems that the compressor is shot. We’re taking a road trip in 3 days (to the Everglades!), so I’m having it and the dryer replaced. $1700. Ugh, but at least it’ll be going again. They did say my alternator is failing too, but I’m going to try to swap that out myself when I’ve got the time to get into the weeds.
 
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