2003 Suburban Rear Door Lock problem

Have the actuators checked, they could be weak and not allowing the doors to be locked. Check lubrications and alignment of actuators.

How would one tell if the actuators are weak. Also if the rear door relays are working correctly? Is the relay used in the power on position to unlock doors, or power off? Is this a dealer only option?

The rear door lock and unlock uses different relays for locking and unlocking. hey are located in left instrument panel fuse box (lower left side of dash). They can be tested but the easiest way is to swap them around and if problem changes to unable to unlock, then we know the relay is bad.

For actuators, you need to remove the door panel and disconnect the actuator wires and test with battery voltage.

I believe that part cn be sourced from parts outlets.

Sorry I forgot to attach the diagrams.

Your help is appreaciated. The problem was the relay, swapping the relays caused the 4 doors to lock, and only the two front unlock. I can live with that until I replace the relay. Thanks a bunch.

You're welcome.

Have a nice day.

OReilly had the relay at 11.74 with tax. The car is working great now. I will use your service in the future. Great!!!

Cheers.

Have a great weekend.