2001 V70 A/C Problems & Questions

[bubbatex]

I searched, but most of what I found was related to later models. My 01 V70 T5 has the a/c cutting off problems that has been listed on older models. Now that is it warm again here in TX, the A/C cuts off in stop-n-go traffic and I have to turn it off for 3-5 minutes to get it working again. It will work again for a few minutes and then cut off again. The blower works fine. This will continue until I get on an open road. It works just fine on the highway. This happened about 2 years ago and they replaced the cooling fan that was on recall. All has worked well since then until the past few months. I use a small shop for service and repairs (cheaper than dealer) - they could not reproduce the problem in the shop, but recharged and oiled the clutch, but it not not seem to take care of the problem. What else should I look at before they replace the compressor. Seems to me that if it was the compressor, it would not work on the highway. Thanks!