Oldsmobile/Buick Repair: 1990 Buick Regal Brake Lights do not work, turn signal switch, buick regal

Question
The third light (in the rear window) will light when the brake pedal in depressed but the brake lights at the rear of the car do not.  I have replaced the bulbs with new and they still do not work.

Approximately two years ago I had to replace the turn signal switch under the steerting wheel because the turn signals would not work properly.  Could this switch be part of the problem?  When the hazard lights are turned on all the bulbs flash in the rear lights except the centers, is this normal.  One other question, is there only one stop light switch on the pedal or does the third light have it's own switch.  I'm at my wits end trying to fix the problem.  Thanks in advance for your help.

Answer
The high mount stop light is working as it should.
The other stop lights do pass thru the turn signal switch.
Make sure the connections are tight at the connector down the steering column.

The hazzard flashing is correct. It also indicates the bulbs, socket connectors and grounds are all good, and points toward the turn signal switch.

Van