I'm working on a 1998 Ford Contour with a right rear turn signal that is acting up. The indicator on the dash and the right front turn signal are quick flashing while the right rear signal/bulb is on solid. It worked for a while after changing the bulb, then it was on solid again. While removing the socket and bulb from the housing for further examination, it started blinking. Manipulating the wires with the socket back in the housing failed to trigger the solid on behavior, but closing the trunk lid did. Cleaning the contacts in the socket and adding bulb grease seemed to help for a while, but it was soon back to being on solid when it should be blinking. The socket is discolored, apparently from overheating at some point in the past. Probing the wires with a multimeter is going to be tricky, since it starts working as soon as I touch it.
Any suggestions?