Tail light problems....

[E_meola]

Started about a week ago

Right rear blinker not working intermittently (fast flash in dash ind)
changed bulb even though it seemed to be fine checked socket connection with multi meter and see the rapid blink in connections.
tried hazard lights and both sides blinked...

now both right and left rear not blinking no hazard blink no break lights but I do have tail lights (parking lights) on rear...

plug trailer into connection and trailer lights function normally blink tail break hazard......I'm stumped anyone have any ideas?

[E_meola]

anyone have any ideas?