fuse #21 keeps blowing, has a dead short need a wiring diagram

 

For my 1993 600, per www.alldata.com, Fuse 21 is 15amps and has following cicuits: Power/heated mirrors, windshield wahser heater, parts of the A/C, and trans cooler control(?). Does the fuse burn out only with the ignition switch on/engine running?
www.alldata.com has the wiring diagrams.