A/C Help

[Jimmy Brooks]

Before I start this off, this is a post about a D5 AC system which I believe to be pretty similar to the LR4 system (same SCV6). ANYWAY…

Just replaced the O2 sensor on my parents D5 and everything was well. About a week after I got into the car and the AC system just doesn’t work. No codes, no smell of Freon, it’s as if the system is just completely off which makes me think it’s a relay. Non of the fuses that go to the AC system are blow but the fuse diagram in the owners manual doesn’t include relays. The system never showed any symptoms of low Freon or a bad compressor, it has 63k on it too so I don’t think that would make sense.

If anyone has else has any pointers I would appreciate it, a relay diagram for that car would really help me as well. I’m going to try to recalibrate the ac blend motor tonight, but I doubt that will do anything.

 

[jlglr4]

Does the blower come on, just no ac? What about the little light that indicates ac? Stays off when you toggle ac on/off? If the blower works, I tend to agree that it sounds like the clutch relay or the solenoid clutch in the compressor itself (though could also be wiring). On the LR4, looks like the clutch relay is 14E and fuse is 11E. Not sure whether those are in the engine bay or under the dash, or whether they are the same in the Disco 5.

If you haven’t already, I would check for TSBs on the issue, and check for any OBDII codes - sometimes codes will set that power systems down for protective reasons.

Someone posted up an electrical diagram for the LR4 here: http://bee.mif.pg.gda.pl/ciasteczkowypotwor/#samochody/Land Rover/D4 Wiring Diagram 2011.pdf

I don’t have the Disco 5 diagram.

 

[Jimmy Brooks]

Does the blower come on, just no ac? What about the little light that indicates ac? Stays off when you toggle ac on/off? If the blower works, I tend to agree that it sounds like the clutch relay or the solenoid clutch in the compressor itself (though could also be wiring). On the LR4, looks like the clutch relay is 14E and fuse is 11E. Not sure whether those are in the engine bay or under the dash, or whether they are the same in the Disco 5.

If you haven’t already, I would check for TSBs on the issue, and check for any OBDII codes - sometimes codes will set that power systems down for protective reasons.

Someone posted up an electrical diagram for the LR4 here: http://bee.mif.pg.gda.pl/ciasteczkowypotwor/#samochody/Land Rover/D4 Wiring Diagram 2011.pdf

I don’t have the Disco 5 diagram.

Everything acts as if the AC is working it’s just the air is not cold, it’s as if the A/C button isn’t clicked.

Blower motor works great and ac light turns on, just no AC.

 

[scapistron]

Does the clutch engage on the compressor? Did a mouse eat the wires?

 

[Jimmy Brooks]

Does the clutch engage on the compressor? Did a mouse eat the wires?

I believe it does, how would I check to see if the clutch is engaged?

 

[Jimmy Brooks]

Went back into the D5 this morning and turned the AC blower on low. When I toggle the AC switch on I can hear a slight hissing coming from inside the dash when the A/C button is toggled on. When I say Henning, I mean, it’s very similar to the noise you hear when you stand next to a house is natural gas valve. Any ideas?

 

[scapistron]

Probably the sound of refrigerant expanding. PV=nRT

 

[Nechaken]

I suspect, if the car is warmed up and at regular (low) idle, there might be a tiny blip in rpm when you turn the AC on as well.