I just bought a 1996 toyota avalon every thing on

Turn signals and hazard lights are 2 totally different switches. You basically verified that the flasher unit works, but the turn signal switch is broken.

Sounds like you lost the ground to the rear lights.

The turn signal and brake lights are controlled by the turn signal switch.
You did not mention parking lights so I will assume they work.

Could be a faulty turn signal switch or a wiring problem between the dash and the rear of the van.
Do the hazard flashers work on all four corners ?

bad suspension in the rear

Check this for 1996 Toyota Avalon Car Stereo Radio Wiring Diagram Radio Constant 12V+ Wire: Blue/Yellow
Radio Switched 12V+ Wire: Gray
Radio Ground Wire: Brown
Radio Illumination Wire: Green
Radio Dimmer Wire: N/A
Radio Power Antenna Trigger Wire: Black/Red
Radio Amplifier Turn On Trigger Wire: N/A
Front Speakers Size: 5 1/4" Speakers
Front Speakers Location: Doors
Left Front Speaker Wire (+): Pink
Left Front Speaker Wire (-): Purple
Right Front Speaker Wire (+): Light Green
Right Front Speaker Wire (-): Blue
Rear Speakers Size: 5 1/4" Speakers
Rear Speakers Location: Rear Doors
Left Rear Speaker Wire (+): Black
Left Rear Speaker Wire (-): Yellow
Right Rear Speaker Wire (+): Red
Right Rear Speaker Wire (-): White

Hope helps (remember to rate and comment this free answeer).

How do you remove the tail ligh housing from a 1996 Toyota Avalon?

Your brake light is on because your brake fluid is probably low in the brake master cylinder. As the brakes wear, the fluid level drops proportionally. A switch in the brake master cyluinder measures the fluid level.

The //\\ light indicates you have a burnt out tail or brake lamp. All of the rear lamps are checked by a sensor, including the one in the rear window.

which light bulbs were changed? recheck all that were replaced. do the hazard lights work?

it means you have a rear tail or brake light out.

Check the front lights. Usually if i flashes fast it indicate a bulb is out on that side.