Armand:
This webpage has schematics & diagrams for dewalt drills, though i didn't see yours, there are some that are basically the same, here is a diagram for the 505k,
http://www.toolpartsdirect.com/cgi-bin/schematic.cgi/dewalt/DW505_TYPE_1
you can also order parts from them for whatever you need. (i never have, but they are authorized dealers)
ryan, August 2008