Dan:

Don't know what year your Vanagon is, but the typical wiring for
the brake lites is from a fuse to the switch to the lights.

In '87, it is fuse S15, then out connector D, pin 16, to the
brake lite switch, which is up under the dash--part of the
brake master cylinder, pedal linkage, etc.

Again, in '87, the wire from D16 to the switch is Bk/Gy and
from the switch to the engine compartment and bulbs, Bk/Bl.

Check that you didn't accidently pull off the connector from
the brake lite switch when you were pulling on harness D.
D is the white connector plug into the fuse panel.

Good luck!

                                            Richard A. Jones
                                            '81 Vanagon  Mr Bus
                                            '87 Syncro Westy