Have you checked the wire harness that runs under the drivers door sill plate? The wires for the rear lamps are part of this harness and it is prone to damage and corrosion problems. I have also seen faulty lamp sockets cause this symptom. Check the sockets for bent contacts, damaged wires, or evidence of heat damage (burnt or melted spots). Be sure to check both the turn signal bulb socket and side marker bulb sockets, these lamps are on the same circuit,
Thank you for your question. These are a couple of ideas, please let me know if this helps or if you have any other questions.
Saturday, January 15th, 2011 AT 6:50 PM