1999 express van,
When the lights are off, the brake lights are work fine.
When the lights are on, the brake lights are on, when u press the pedal the lights go off.
The center light above the door works correctly?
Any suggestions??

Thanx, Mike

:D

Trailer wiring ??

I had the same problem with my van, 2000 express 1500 conversion.

it seems that the wires entering the bulb sockets get loose or they rot from moisture after a few years, I jiggled and pushed them into the sockets, then tested them and the problem went away, mine seem to be working fine, but i would recommend replacing them with new bulb sockets....hope this helps.