90 aerostar turnsignals

one night my turn signals stopped working. the fuse was blown. i replace it and it blew again immediately. next day I replace and checked out all turn signal and indicator lights. didn't work. i replaced the turn signal switch. it didn't work. i replaced the ignition switch. it didn't work. the funny thing is sometimes i can get up in the morning. change the fuse, it doesn't blow and the turn signals work perfect with the switch on, sometimes even with the engine running. but as soon as I put it in reverse the fuse blows and it will then blow the fuse even if I turn the engine off and it's in park. I'm going bankrupt on fuses. the brake lights work great, as does the running light. only the turn signals and the back up lights don't work. I also tried disconnecting the back up light switch on the side of the transmission in case it was shorting out the wires but it did not work. the turnsignal fuse keeps blowing. perplexed

You probably have a damaged wire between the switch and the turn signal lamps. Since you are also having trouble with the back-up lights, I would suspect the part of the harness going to the rear. Look at wiring diagram for your vehicle. Make an enlarged copy and highlight the affected circuits. If possible uplug parts of the circuit and see if the fuse still blows.

see if one of your buckets is full of water.