I have a 1992 chevy k1500 extended cab 350 with a manual.
I have replaced 2 back up switches now and they keep going bad after about a month and blowing turn signal fuses. as soon as I replace it the reverse lights work fine and the turn signal fuse does not go bad until that switch goes bad again. wondering if anything could be causing that switch to go bad or if there is a whole different problem entirely? I have checked all the wiring through the truck and there seems to be no issues.

 

Are you buying cheap aftermarket switches? Is the case breaking or cracking, is it rubbing against something?