While many are investigating inop heater boxes and other associated cold weather problems, I finally started looking at the inop AC which I have been putting off for quite some time.
First things:
- Vehicle 1981 911 SC, factory air
- all pieces in place
- PO removed York compressor and replaced with rotary compressor of Volvo origin (York came with car in a box of spare parts)
- Cabin fan blower works without problem
- R12 system (R12 is technically illegal here [Australia], but i'll work around that)
First check, static pressures:
Low side : around 10 psi
High side : barely registering- call it 5 psi
Ambient temp 27 Celsius
Second Check ; engine idle
Low side : no change
High side : call it 10 psi
Revving engine to ~2000 rpm makes no difference to high side pressure.
Third check : vent temp
Essentially no change : cabin ambient was 25/26 Celsius
Fourth Check : Compressor clutch function
Compressor is activated when AC switch is turned on.
Finally, for laughs, I attached the gauges to the DD just to make sure the gauges were working as expected:
That's a static check of R134 in the same garage on a car with working AC.
Conclusions/Questions
- Obviously the gas is low
- Can any conclusions about the compressor be made with the gas so low?
- Is there any risk in having run the compressor with gas so low?
- Is next logical step is getting gas topped up and see where we are at?
My aim is to get factory AC working and assess from there on the need for upgrades.