Blinker problems with 97 Camry

Sounds like you may have the wrong bulb installed causing feedback to both circuits

The problem is caused by the emergency flasher unit. This is a common problem and you can find a few youtube demos on replacing it. I did it in about 30 mins. I don't remember the cost but it was stocked at my local chevy dealership.
good luck.

replace multifuntion switch

get the back working it will no longer fast blink change bulb and check with metre see are you getting power to it also check grounds

bad earth on the back light ,thats all easy to fix clean contacts

start by checking the front wiring harness for corrosion , best is to do a continuity test on all the wires, look for corrosion in connecting harness, time consuming but the only way

Usually a fast turn signal means that there is a light out. You should probably check all of your lights, including back-up lights, and turn signals. If there is one out then replacing the burnt out bulb should fix the problem.

hi usurally when that happens that means you have a bad bulb or bad wiring.

If a dual element bulb develops a condition where both filaments touch together even momentarily will produce a fast flash too. Replace the offending bulb.

If the problem occurs on either side, the blinker relay is getting tired.
These are mostly located under the dashboard and may be in a cylindrical can plugged into a mating connector.

If it is happening only on one side, you may have a corroded lamp socket or the bulb itself.
When the standard thermal blinker relay is used and a problem with contact or a complete bulb failure occurs, your dash indicator will blink more rapidly than usual since the blinker relay is dependent on having a certain amount of current flowing through it which controls the blink frequency.