Rear Running Lights Out

I do believe you have individual fuses for the light assembly on your car. I know newer ones do. You might want to check them first. You have a panel under the hood and one under the back seat. Both will be marked under the cover.

Must be a bad connection if the bulbs are ok.
Are they the right bulbs? Are they in correctly into the sockets?
Do the headlights work?
Check to see if they're on a separate fuse.

With the age of the car it could be that your grounds are bad somewhere which explains why essentially no lights work ... even though the bulbs/fuses are OK. You get power to these lights by having positive wires going to the light bulbs and the negative side of the circuit coming from the frame of the vehicle (referred to as the ground).
Pull all the connectors that you can see and make sure they are not corroded.
Check also that no associated relay that has anything to do with the rear lighting is not bad.

The third or High Mounted Brake Light runs straight off the brake light switch on the brake pedal arm. You say you tested the "brake unit"? I assume you mean the third brake light assembly, and if you get power there when someone steps on the brake pedal, then the bulbs are bad.

The power flow for the brake lights goes like this: Fuse ->Brake switch -> Turn signal switch -> Rear lights. The only difference is, if you have a 3rd brake light in your rear window, that gets its power directly from the brake switch. It does not go thru the signal switch first. So, if you are having a brake light problem, and your fuses are good, check the 3rd light in the rear window, if it lights up (assuming the bulbs are good, no one ever changes them), then the problem is most likely in the turn signal switch, hope this helps!

Have fitted the proper bulbs some have a staggered pin on them only go in one way

Your turn signal lights and brake lights are the same lights . Question : do the front parking lights work ? The front and rear running lights or parking lights are all on the same circuit and fuse . If the front lights work , and the rear lights don't , make sure the bulbs are good first . If OK , I would suspect the problem is either a bad ground in the rear taillight wiring harness or a bad connection in the rear taillight connector Itself .

the brake lights and the rear turn signals should be the same bulb check the bulbs to make sure they are not blown does your third brake light work if all brake light are out and the bulbs are good check the brake light switch on the brake pedal

you prob got a trailer plug prob bad wires if not tail lights run through turn signal switch tell fix ya bout me ok

You have a broken wire to the turn/brake light portion of the light as they use the same wire. Or where the plug goes into the light assy could be bad. Torsion mount lights are horrible and you should think about replacing with a universal light that you can wire direct.