The first thing that comes to mind is either a brake light bulb that
has been forced into its socket incorrectly (long section forced into
the short section of the socket housing, you'll see what I mean when
you pull one out) or a poorly constructed bulb (extra solder
externally/internally) is causing a short.  In any even, pull each
brake light bulb until the problem is found.  That's my guess.

Wil

whene you say parking lights are you refering to the side marker
lights? check the ground wire in the tail light assembly. if the
ground wire is loose you will get feed back through the combo switch
lighting up the side markesr or turn signals. I have seen this on
earlier max's and alt's

Spat