The left side lights break lights and left signal are all out i tried changing the bulb that didnt work what should i do i heard that it could posiley be a computer problem how do i fix that.... thank you christina

check for a problem ground for that light as it is grounding out through another light circuit

Has the vehicle been in an accident on the left rear side. First check the bulb to be sure it is not defective, trade it out with the side that works properly to test. If the bulb works well then My thought are you may have a shorted wire. The turn signal flasher works by heat build up within the flasher the heat is caused by the load of the bulbs, the load heats the metal spring causing it to open the circuit then as quickly as it cools down the circuit closes again lighting the bulbs.
There is also a possibility of a defect in the turn signal mechanism on the steering column. The turn signal switch on many models does three different things on many models that use the same bulb element / or bulb for brake and turn on rear of vehicle. It controls the circuit for brake light by sending power both left and right side rear when turn signal is in neutral position then when turn signal is in left turn the switch cancels brake light power to left side rear and supplies flasher power to left side while maintaining brake light supply to the right side rear, and so on opposite when the right turn is chosen on turn signal switch. The turn signal indicators on the dash normally run off the same circuit as front turn signal bulb only which is also controlled by turn signal switch. Front has turn signals but no brake light.
I think there is an additional load on the left side rear turn circuit and it could be either a wire that is shorted or the turn signal switch if the same bulb element is used for both functions.
Often times if trailer lighting is connected the flasher will also blink a little faster because of the extra load of additional bulbs.

ater painting , I would be suspecting that a ground point has paint under the contact and is nor making a good ground
also check that the wires are properly connected in the harness

yes but first check the bulb

vehicle?????????

No, because the left side is still working. The loose wiring was to the multifunction switch (turn signal).

Power gores through the turn signal switch to the brake switch on the brake pedal, then to the rear lights. Does the highmount brake lamp work?
At the RH lamp socket, Measure the voltage between the RH rear lamp C4032 pin 3, circuit 5 (OG/LB), harness side and ground. Should be 12 volts.

try that first.

Did you change the front and rear bulbs?

sounds like a electrical issue never heard such a thing

Replace the turn signal switch. Bad contact inside causing a crossing of the circuits. When the turn signal is applied it should open the brake light circuit allowing for just the signal to work. Doesn't sound like the switch is doing it's job.

Both bulbs have to be new. They can't be different ages. Change the flasher as well.

turn on the hazard light so you can identify the bulb that is actually deffective. the procedure to replace can be found on youtube.