no leftside brake lights at all

have a 1994 berretta the left side brake lights do not work
the turn signal works the bulbs have been checked and replaced with new one also tried them on the other side they worked the fuse is good
the light do not come on when the headlights are turned on
what should i check to fix this problem be side replace the whole rear wire harness
what color wire should be hot when the brake lights are on because the brakes have beeb applied what color wire is hot when the lights have been turned on:naughty

It's a combined brake/flasher light, so the problem is a bad contact in turn signal switch. Cause brake signal goes through this switch to light up the lateral brake lamps. 2 switches, one for the left, other for the right.

While you're braking, try to pull the turn signal or play it up and down. It may light up.

I'm sure the problem is not in the wiring. Cause it flashes. It's the same bulbs.

About the park/head light, it may be a problem with the harness.

When you press the brake pedal, the yellow wire is hot for the left lamps.
When you turn on the park/head light, the brown wire is hot for the left lamps.

Replace the turn signal switch.

You can see the electric schematic at autozone:

http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/0a/76/ab/large/0900c152800a76ab.gif