A/C doesnt work after car wash

Howdy all. Just purchased an 05 Avalanche.  Nothing special, 2wd, no cladding.  Love the vehicle so far but have one recurring problem.  I live in Texas and we have had a really bad crop of love bugs this year.  I have about an hour commute back and forth to work and truck gets covered with them.  Usually stop at a local car wash and spray the bugs off, but every time I do, the a/c wont work for a while.  Ive read about the outside temp sensor, and Im sure its getting wet, but i try to avoid getting that spot really wet, but still, ac never works.  Sometimes its just a mile or two and it will start working, but sometimes it takes longer, like overnight.  Anybody have a secret for keeping the sensor dry?  Thanks in advance for any input.

Im no expert but my thought first would be refrigerant level. Maybe low?

Are you sure it isn't a slipping belt?

Man, I thought along the same lines of a freon issue, but after posting earlier, I went out and pulled the a/c relay to check it.  Looked ok and put it back in.  Cranked truck, and ac worked just fine.  Very strange.  Gonna replace relay just in case.  See if it happens again.  Thanks for response sir. 

Enoniam, hadnt thought about a slipping belt, but will check that next time.  Thanks. 

Next time it happens check Check if AC clutch engaged or not.

If the bugs are that bad, maybe the condenser is blocked...