electric problem with turn signals and reverse lights

Hello all.. THis is my first post to this forum. I have a 1995 buick lesabre that has a small problem of blowing a fuse(for the turn signals) when I put the car in reverse. This problem is intermittent and only happens when the car goes into reverse. My question is has anybody ever dealt with a situation like this before, and where would I look to find the possible short? I've looked in the trunk at the harness for reverse lights and turn/brake lights, but haven't noticed anything odd. It gets expensive replacing the mini blade fuses.

Thanks in advance for the help.