Yesterday was a hot day (Victoria, Australia) - aircon now blowing hot air! Not good!

Understand the basics of aircon, but managed to get free practical advice and diagnosis from someone who was a motor mechanic - conclusion: need new compressor and probably wise to install a new receiver/drier as well! $$$...

Okay, here are the facts:

• 2003 Discovery 2 (D2a) Td5 with the original factory-fitted aircon (think it's a Denso?)
• Aircon extends to back seats via 2nd evaporator unit in the rear
• Confirmed no gas leaks and currently confirmed fully-charged with 1,1,1,2 - Tetrafluoroethane (R134A)!
• Interrogation (holding two buttons) of climate control panel shows no faults
• Foxwell scanner shows no faults
• Relay and fuse good
• Electrical connector on compressor removed and checked with multimeter - electrical supply to compressor okay
• Clutch was engaging several weeks ago and then around a week ago went sporadic and now has stopped engaging
• Can turn clutch by hand (not seized)

Does this mean new compressor required? Looking likely?

Okay, if it does, in order to save a bit of $$$ (have had to fork out a fair bit on other things (non-Disco) recently), can I do it myself? Buy new compressor (+ 2 o-rings for top LP and HP ports), buy new drier/receiver (borderline serviceable item I was told) and then what?

Illegal (and can be dangerous if you have no idea) to degas to atmosphere, so I assume I take her to an aircon tech to collect the R134A? Then what?

Remove both compressor and receiver/drier - easy job? Then install new compressor and receiver drier, and recharge with R134A?

Has anyone done this themselves to save some cash? Easy/hard? Guide/tutorial anywhere?


Any advice would be appreciated as I now have to go to the next step and hopefully resolve this issue before the hot days come along thick and fast!

Intestinalworm said:

• Electrical connector on compressor removed and checked with multimeter - electrical supply to compressor okay

• Clutch was engaging several weeks ago and then around a week ago went sporadic and now has stopped engaging

Click to expand...

So, corroborating the two bolded parts... if you get 12V to the clutch connector and no activity then i'd rather blame the clutch than the whole compressor, do somehow to measure voltage with needle probes while the clutch connector is plugged in... if no voltage drop nor any click or activity then the solenoid is very suspect

sierrafery said:

So, corroborating the two bolded parts... if you get 12V to the clutch connector and no activity then i'd rather blame the clutch than the whole compressor, do somehow to measure voltage with needle probes while the clutch connector is plugged in... if no voltage drop nor any click or activity then the solenoid is very suspect

Click to expand...

Okay, will need to get needle probes (auto) to test in from the back of the connector. When you say solenoid, that's the doughnut-shaped coil that is supposed to energise and pull back the clutch so it grips with the pulley and therefore turns the compressor shaft?.

Intestinalworm said:

When you say solenoid, that's the doughnut-shaped coil that is supposed to energise and pull back the clutch so it grips with the pulley and therefore turns the compressor shaft?.

Click to expand...

Exactly, there are case when the clutch is seized but then the solenoid gets feed and in some cases you can hear a faint click or if not there is a serious voltage drop when it's powered. If no voltage drop the solenoid is gone....

• Can turn clutch by hand (not seized)

Click to expand...

the fact that you can turn the pulley while the clutch is not engaged is normal cos it's supposed to idle, to see if the compressor is seized you have to turn it's shaft which turns only if the clutch is engaged.

btw... you can insert sewing needles into the connector or wires and measure on those