Probably by checking the wiring loom and connectors for damages and and corrosion.
In the back of a Haynes repair manual or autozone.com there you will find online repair manual's
Try cycling your electric door locks with the key removed from the ignition.
TAke the trim pad off and see what is wrong with the linkage. Probably need an door actuator kit
The relay switch for the locks on a 99 Chevy Suburban is located under the driver-side dashboard.
Call a locks-smith.
Wrong kinda locks. Locks need to be upright.
Electric doors?? Are you talking about door locks? If so, even though they are electric, you can still operate them manually. Disconnect the power to the door locks and they are then manual.
You take it to an auto shop and have them do it
I am not sure. My 05 locks will not work at all after I changed out my bad battery. driver side window will not work either. looks like I will have to pay a vsit to the dealership.