Warming up the Bonnie today to go ice fishing, I go back out and car wasn't running. Open the hood and serpentine is just laying there, under the alternator, a plastic tensioner was broke off. Question, there is a bolt just attaching it, can just the wheel be replaced, or does the whole thing need to be replaced, and how much is it gonna run to fix??

Does the pulley spin? If so, then you can change just the pulley. You can check on www.rockauto.com for a new pulley.

Got it fixed the other day at the local Chevy dealer where I bought it, $148 so it wasn't too bad.

Wow, hope you got a new tensioner for that and not just a new pulley.