Thread: D4 A/C Compressor issue

well this is the reason i actually posted this. natrad tech says ok, and i tend to agree, as there is the clutch inside the pump that when the ac is off (or there is no gas pressure as there will be once removed) afaik disconnects the drive to the pump itself, this needs to be there to stop the pump destroying itself if you leak all your gas.

Originally Posted by haydent

well this is the reason i actually posted this. natrad tech says ok, and i tend to agree, as there is the clutch inside the pump that when the ac is off (or there is no gas pressure as there will be once removed) afaik disconnects the drive to the pump itself, this needs to be there to stop the pump destroying itself if you leak all your gas.

There is no clutch inside the pump. If the pump doesn't have a clutch on the pulley, then it is always running even if at minimum displacement (~5%).

Edit: The LR020449 part number you quoted shows images of a Sanden compressor *with* an external clutch.

Edit2: It cross references to a Sanden PXV, which has an external clutch and internal displacement control. So the car has no control over the displacement, the compressor manages that internally based on the suction pressure. The car simply switches it on and off.

The oddities that are differing Land Rover engine configurations. Didn't realise yours is a V8. As you were...

LR020449 - COMPRESSOR ASSY | LR Parts
thanks for your input, i thought it was displacement car controlled as well, as in iid tool it shows changing output for clutch status and ac compressor current, which im told the unit is wrong but that is the displacement reading. but ive never looked at it when not working, so maybe it just always is either 255 or 0, as an assumed displacement value rather than a measured one.

*update see later post LR020449 is for l322 not l320 despite same motor...

so whats to stop one without a clutch destroying itself if you run out or leak all your gas ?

Originally Posted by haydent

LR020449 - COMPRESSOR ASSY | LR Parts
thanks for your input, i thought it was displacement car controlled as well, as in iid tool it shows changing output for clutch status and ac compressor current, which im told the unit is wrong but that is the displacement reading. but ive never looked at it when not working, so maybe it just always is either 255 or 0, as an assumed displacement value rather than a measured one.

If it's displacement controlled there will be 2 connectors to the compressor. One for the displacement valve and one for the clutch. The Sanden PXE series does say it's "internal control variable displacement".

Swash Plate Type / PX series | Products | SANDEN

Just another "thing" to get on top of.

For the record, what precisely is it you are driving and with what engine configuration (3.6V8?). I can't find that on any of the Disco wiring diagrams I have here, which is what confused me.

*update see later post LR020449 is for l322 not l320 despite same motor...
i did post here D4 A/C Compressor issue
l320 2010 tdv8
LR020449 sanden pxv16 8649e

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Originally Posted by BradC

On a D3? No. According to the wiring diagram the D4 has a clutch on the compressor (controlled from Relay R181 in the engine bay fuse box. Fuse 11E apparently) along with the variable valve.

So you’d have to flatbed it to the AC shop?

Originally Posted by haydent

so whats to stop one without a clutch destroying itself if you run out or leak all your gas ?