NO flash or brake light 2013 F150 Platinum
 

My left turn signal flashes very rapidly. ALL fuses under dash and under hood check OK (checked with a meter AND light probe). Front amber flashes rapidly, LED's on mirror flash rapidly and the flash arrow in the instrument cluster for left turn flashes rapidly BUT the rear does NOT flash at any rate. Checked for voltage at factory installed trailer sockets - NOTHING. Running light comes on... 4-way flash does not flash on left rear... left rear brake light does not work when brake pedal depressed right side is OK... I have checked fuses multiple times and replaced any I thought may be suspect even after checking with light probe and ohmmeter. The only thing I haven't checked is the flasher itself BUT cannot find the flasher... any thoughts as to where the flasher is located? Checked wiring at left rear for breaks or shorts... nothing!

Also, any thoughts as to what else may be at fault? I have spent many, many hours over 2-3 days and cannot find any thing that may be suspect that would prevent the left rear turn signal and brake light from working! Keeping in mind the running light works OK on left rear.

If the thoughts on the forum is the flasher... please advise where it is located. I cannot find it!

This is driving me nuts... would sincerely appreciate ANY help or thoughts!