A/C seems to be working well ('03 V70 2.4T) - even in the 100+F weather last week - but, I have noticed that, at idle, it cycles rapidly - 5-6 seconds on, 10-15 seconds off - any cause for concern?

About this business of no high pressure side port: I can't see the cost of a port being an important factor in the overall picture. Is there any reason for it other than making life difficult or providing another lucrative service opportunity?

 

I believe the high side one is on the condenser and low side is by the p/s resovoir. Your not seeing it?

 

I've recently been working on the A/C in my car (2001 V70 T5) and my it does cycle on and off at a similar rate that you described, maybe not off for a quite as long but the cycle on period is 5 to 6 seconds at idle and a lower fan speed setting. I do have A/C gauges and I can see the compressor pull the low side down to ~30psi when it shuts off. I also thought this cycle rate was high but the gauge readings for my A/C look good and this is after evacuating and recharging the system, I do have a slow leak somewhere.

What I've read in my Hayes A/C book is a high cycle rate could be a due to a low charge or a restriction in the low side somewhere such as at the expansion valve, some have screens that clog up, not sure if the Volvo does though. If your A/C is working well in hot temperatures your charge level must be good. I also wouldn't suspect much of a restriction either since the A/C is working well. I attached pictures of the high and low side ports location for my car. High side port is next to passenger headlamp, low side below the P/S reservoir.