Hi. First post.
I just picked up a 06 Suburban 1500. No owners manual. 148K miles.
The rear hatch works fine. Just doesn't lock. Before tearing off the rear hatch cover panel, Is there a fuse for the rear hatch lock actuator.to check first?
Doesn't sound like actuator is doing anything but I wasn't listening real close at the time.
Is this a common issue? One thing I don't like about this truck is no manual locks except for driver door.

 

Our 05 Suburban had the same problem, turned out to be broken wires in the harness coming in to the door. Mechanic said it was a common failure point do to motion every time the door opens & closes.

 

I removed the rear hatch panels and found the actuator is getting power. I hear/feel it moving or trying to.
I will go ahead and order a new rear hatch actuator. In the meantime I was able to manually lock the rear hatch

 

For what it's worth: a few years ago I bought a 2001 Yukon XL with barn doors. I went through it and got everything working big and small. After a year, the one thing I could never figure out was the doors, they wouldn't lock. Tried everything, pulled everything apart....no luck.

Then one day the Mrs. pulled in the driveway and I noticed one of the back license plate lights were out. I replaced it and from that day on the doors have worked perfectly. I have no explanation, other than problem solved.

Tom

 

Replaced the rear hatch lock actuator today. It definitely was the actuator but thanks for the other suggestions.
Back in business. Easy and painless swap.