Thread: D4 a/c not cooling

103 PSI is close enough to ambient at the moment. Have you put gauges on it? What is the low and high side? Unless they are close, I'd be inclined to look for a leak. Either the compressor isn't compressing or there's bugger all there to compress.

I did a recharge on our D3 just after we got it, which turned up a leaky service valve.

Thanks for replying.
We don't have gauges. My understanding from the WSM is that the pressure indicates adequate refridgerant but we may have to get the pressure checked. There are no pressure faults, low or high.

We're confident that the compressor isn't pumping anything worthwhile but not being able to check the signal to the valve we can't tell if the compressor is or isn't being instructed to be at minimum displacement. That the system worked well some 2 weeks ago when last started, many months since the system was regassed, suggests that the fault is electrical/electronic rather than lack of refridgerant.

The 2 calibrations have been done and all the controls appear to work so I'm wondering if something such as WOT condition is met, which suspends a/c operation.

Does anyone know if the LR diagnostic tool can monitor the signal to the compressor control valve? The IIDtool doesn't have such an option.

If the compressor is definitely turning over and keeps operating,at those pressures,it maybe not pumping.

Are the High and low side pressures the same when the compressor is operating?.

Edit,Sorry Graeme,didn't see your post above.

Originally Posted by Graeme

Thanks for replying.
We don't have gauges. My understanding from the WSM is that the pressure indicates adequate refridgerant but we may have to get the pressure checked.

Not really. Refrigerant pressure is a P/T relationship between liquid and gas. There can be 2/10ths of **** all liquid, but as long is there is *some* the pressures at rest will be the same. So the D3 needs ~550g of refrigerant. If there was 100g of liquid the pressures would be the same at the same temperatures (at rest). If the compressor was running however there'd be not much on the high side and the low side would be in vacuum.

While it's nice the car gives a high side pressure, without a low side pressure you're a bit in the dark. Whacking a set of gauges on you should be seeing ~>200 psi high side and ~50psi low side. (Ambient +20-30c on the high side and ~4-6c low side).