If your parking brake light is staying on then my guess is that you need to take your parking brake off. Sometimes on Chevy trucks the parking brake can stick. Check for sticking first, then i would check the sensor
This could be caused by two thing. First off check to make sure the switched is working properly. Next make sure that the cable is not binding up and is properly lubricated. It may be sticky an not fully releasing.
Look on the parking brake- there is a switch on the arm some where, the switch sounds like it's stuck in the on position or it could be a total brake issue, check the brake fluid level also.
