I have an 05 Trailblazer with 198,000 miles that are having electrical issues. The problems are intermittent and affect the turn signals, gas gauge, and rear ac/heat unit. Sometimes these items do not work but will begin working again. The truck was in a front end crash and I do not know if these issues were present before the crash. We cannot find any loose connections or grounds. Could this problem be in the BCM? Where can I go from here?