Just as a test, try disconnecting the electrical connector from the transmission kickdown switch (under the accelerator pedal) and see if that stops the fuse from blowing. My 1984 300TD was randomly blowing the #14 fuse and after a lot of troubleshooting I figured out that the reference to "automatic transmission" on the cover had to be the kickdown solenoid. My kickdown solenoid was bad and every time that I floored the accelerator and it hit the kickdown switch, the fuse blew.
