Toyota Repair: A/C switch, backyard mechanic, local shop

Question
I have a 94 pickup with V6. I recently had the A/C repaired by a local shop and it was working great for a week. However, I was on my way home and noticed that the light on the A/C switch was not lit up and I could not hear my flex-a-lite fan running. It wasn't until I was nearing my house that I noticed the light on the A/C switch was now on and the system was blowing cold air. I tried playing with the blower lever and placed it in the off position and the light on the switch would stay on. I plan on taking my truck back to the repair shop but before I do I would like to know if this is something simple that I could fix myself.  

Answer
My recommendation is never attempt to repair work that another Shop has repaired. Always hold the shop accountable to their workmanship. If you do attempt to repair their workmanship, they may void their warranty and  any repairs related to the system claiming it failed due to your tampering. If a backyard mechanic did the repairs then of course you would have to look into it yourself, but for services charged, serviced warranteed.