i have a 2017 chevy Silverado crew cab short box 1500 5.3l engine...THE PROBLEM: the left rear door lock dosent work... will not un-lock or lock... ive owned a number of chevy cars and trucks..all have had this problem at one time or another... the truck is the texas edition so eletric every thing... NO SUN ROOF... ANY HELP ON WERE TO LOOK AND WHAT TO TEST WOULD BE OF THE UP-MOST OF PLEASE AND THANK YOU'S...

 

Check the fuse for the door locks first.
If the fuse is good, remove the door panel and check the wiring going to the lock.
Look for broken or loose wires near the hinge area.
If the wiring is fine, test the door lock actuator with a meter to see if it gets power when you press the lock switch.
If it gets power but does not move, the actuator may need to be replaced.

 

it is usually a dead actuator or a broken wire in the door hinge boot wiggle the rubber boot between the door and frame while hitting the lock button if it moves the wiring is cracked otherwise the latch actuator is likely toast