A/C Problem with Relay

After I had my 2002 Trailblazer about 2 months. There was a problem with a relay that switches the A/C on. Occasionaly I would start the TB and the A/C didn't work. Then I would kill the motor and restart, and the A/C worked fine. I brought the TB in for warrantee work, and the mechanic realized right away it was a bad relay. It was replaced and I went two years with out problems. Now I'm having a similar problem, in addition to having a bad actuator. Sometimes, while were driving the A/C quits, the fans still blows, Sometimes, it will come back on after 5 minutes, sometimes it wont' come back on at all. I've tried cycling the A/C on and off doesn't work. The only way, i've got it to work is by pulling over and killing the motor and restarting. I think I got another bad relay. Has anyone else had this problem?