2004 Mazda 6 Cruise Control

Computer problem
2004 Mazda 6 6 cyl Front Wheel Drive Automatic 35600

I had my brake switch replaced recently, and now my CC doesn't seem to be working. I took it back to the shop to check the Brake switch, and they ran a test on it and said it was good. He said it might be coming from the computer. He said there is no cable that attaches to the Throttle body like some other cars have. The CC turns on, but doesn't seem to engage. I also bought it back to him recently, cause he had to adjust the switch due to the back lights staying on all night. Should I just replace the switch again by myself or let it go. Is it easy to replace? Also is the switch adjustable turning the white plunger dial located near the brake pedal or just pulling on the switch? Any ideas?
Thanks.