GM Repair Problems? Ask GM Repair Expert Now.
Hello and thank you for your question,The common cause for the blower to remain on on your 1/2 ton is usually caused by a failing blower motor speed controller. GM has released a service bulletin as well for this problem which calls for replacing its. I have enclosed the bulletin in the link below for your review. Its located on the AC/heater plenum below the dash on the glove box side. You can unplug it for now until you can get it replaced. See the location and the bulletin in the link bel . Copy and paste the link to your browser to open and view them. The fuse you need to pull is the 40 amp blower motor fuse located in the under hood panel marked blower motor.https://dl.dropboxusercontent.com/u/104923897/Blower%20TSB%20Feb%2023.pdfhttps://dl.dropboxusercontent.com/u/104923897/Blower%20controller%20Feb%2023.pdf