GMC Repair: Serpantine belt, serpentine belt

Question
My serpentine belt came off while driving should I put it back on or take it to the dealer?

Answer
well the first thing is why did the belt come off?? was it improperly installed or is there a failed part causing it to fall off?  If you just had it repaired I would most certainly take it back to the installer and have them make good on the repair you paid for.