Signal Indicator and Door Chime
 

Help! My turn signal and the door chime on my 2008 Silverado don't make a sound anymore. I do have an aftermarket stereo system that was installed about a year ago. Everything was fine until a couple of days ago. Should I replace the chime and wiring harness? I don't think they sell the chime by itself. I looked behind the radio and found the chime and it was connected but why it doesn't work, I would like to know. Any suggestions would very much appreciated. I want the chime back on because it lets me know if i'm forgetting my keys in the ignition.