My dad recently purchased a 96 Rv on a 95 E350 chassis. The hazards and turn signals were not working. I hit the hazard switch with some electrical connector cleaner, and wd40. Now the hazards work, but still no turn signals. My dad had our mechanic look at it; he replaced the turn signal switch twice, and it made no difference. I looked at it after the mechanic. That is when I got the hazards working.
From what I have seen on the internet it seems this is a common problem

 

Check fuse #5 both sides. It is about the only thing it could be.