2011 Silverado Crew cab 5.3L 4x4

Right rear turn signal stopped working. Dash display flash very fast. All rear bulbs have been changed and light with lights on and brakes pressed. Front Right turn signals both flash very fast.
Any thoughts?

 

Inspect the turn signal operation. If the turn signals flash faster than normal, inspect the front turn signals for burned out bulbs. Replace any burned out bulb(s).

Inspect the rear lamp operation. If they do not illuminate, test the circuit for an open.

If the lamps do illuminate but are flashing fast, replace the rear lamp assembly.

If the condition cannot be duplicated, apply and hold the brakes for at least five minutes. Inspect the turn signal operation once again. If the turn signals flash faster than normal, replace the rear lamp assembly.

 

​The rear is 3 different bulb sockets. All 3 bulbs are new. The 2 front turn signal bulbs light up and flash quickly when testing. Could one of those be bad? I have not pulled those out yet due to having to remove air box .

 

well pull one of the bulbs out and test it with a multimeter after you remove the air box

 

Issue solved: It was corroded connection at junction behind rear bumper on drivers side.