1999 camry back up lights

The back up lights don't work until I open the trunk about 6 inches, then they both work.

Open up the loom of wires inside the trunk by the driver's side trunk hinge. Note the color of the wires leading to the backup lights. Check those wires (along with other wires inside there). Chances are you will find they are broken. Repair what you find. The wires inside that loom are exposed to a lot of flexing over the years as the trunk lid is constantly opened and closed. Eventually wires inside there frey and break.

Mike