Intermittent Failure of rear door locks to open..help needed

[09Tahoe4Now]

Okay guys and gals, I need your help. The rear doors are randomly sticking and failing to unlock intermittently. Sometimes they will unlock (more prominently seen in the rear passenger door) and my daughter can get in without a problem, at other times, I’m required to lean the front seat back, reach back and raise up the latch to unlock the door. You can hear the door lock wanting to do its job and see slight movement of the latch but it just don’t pop up. The last time this occurred with the passenger side I simply removed the door panel, made sure everything was on track, reinstalled and no issues until now. To make it worse, the rear driver’s side has decided to get in on the prank!!

I will be replacing the door speakers this week if I’m lucky. So, what can I do to address my two prankish latches? Graphite lube, white lithium grease, wd40....??? I miss get add that this may be a problem that was exacerbated by my daughter pulling on the door handle as I was trying to remotely unlock it. Not 100% sure but it’s possible.

I’m sure it’s a quick fix, I’d just like to knock it out once and not return to it again.

Thanks in advance for the suggestions, replies and knowledge.

 

[Big Mama]

Does the rear switch work? Sounds like the lock button on top may have a broken clip or the rod is loose at the bottom. You can always move the front pass switch to the back to test them.

 

[Doubeleive]

first thing you may want to check is your battery voltage, the resting battery voltage should be around 12.5v, anything under 12v is considered "dead", if the voltage is a suspect try locking/unlocking with the vehicle off and then with the vehicle running to see if you get different results. if that is not the issue and greasing the actuator and any sliders or rods does not correct the problem then the actuators may be getting tired and probably need to be replaced.

 

[89Suburban]

Door lock actuators need replacement.

 

[09Tahoe4Now]

Tested the voltage @Doubeleive and battery @12.7V. Unfortunately the issue occurs with and without the Tahoe running. I wasn’t able to get to the speaker replacement today(enclosed trailer upgrade project, church, Texas heat...don’t play well together), so I wasn’t able to grease the actuators, slides and rods to see if they made a huge difference. I will try that route first and if all else fails, it looks like new actuators like @89Suburban suggested may be in my future. Looks like I was going down the right path *sigh*. It’s awesome when you break things and replace them—but when they just break, it sucks! LOL

Thanks everyone

 

[09Tahoe4Now]

Does the rear switch work? Sounds like the lock button on top may have a broken clip or the rod is loose at the bottom. You can always move the front pass switch to the back to test them.

Yes, rear switch works. Once I get into the door I be able to check the clips.

 

[89Suburban]

Tested the voltage @Doubeleive and battery @12.7V. Unfortunately the issue occurs with and without the Tahoe running. I wasn’t able to get to the speaker replacement today(enclosed trailer upgrade project, church, Texas heat...don’t play well together), so I wasn’t able to grease the actuators, slides and rods to see if they made a huge difference. I will try that route first and if all else fails, it looks like new actuators like @89Suburban suggested may be in my future. Looks like I was going down the right path *sigh*. It’s awesome when you break things and replace them—but when they just break, it sucks! LOL

Thanks everyone

Do not grease or use any kind of liquid lubricant inside the latch area. These are electro-mechanical devices. They are not made for that. I tried it and it seemed to make it worse. Also even the new parts are fragile when installing. Be very careful. The weak links are the tabs the control rods snap into. Keep some sil glyde on hand to lube the rubber grommets the rods go thorough. Will make life much easier.

 

[kbuskill]

Yes, rear switch works. Once I get into the door I be able to check the clips.

Check these out...

2007-2014 GM Door Lock Actuator Repair - Gruven Parts
https://www.gruvenparts.com/2007-2014-gm-door-lock-actuator-repair/

Better than stock IMO.

They have a pretty good video on their site showing how to R&R the lock actuators even if you choose not to get these and rebuild them yourself.

 

[09Tahoe4Now]

Great information!! Better to ask, humble oneself and learn—than to pay the price later!! In my youth I wasted a lot of money, time and great advice by listening to “Nike” and “Just Doing It”! LOL

 

[Ilikemtb999]

Check these out...

2007-2014 GM Door Lock Actuator Repair - Gruven Parts
https://www.gruvenparts.com/2007-2014-gm-door-lock-actuator-repair/

Better than stock IMO.

They have a pretty good video on their site showing how to R&R the lock actuators even if you choose not to get these and rebuild them yourself.

I had sworn I suggested this in this thread but there was another one just a few down from here.

Work great, a bit of a pain to do the rivets if you’re just doing the motor but a welder comes in handy.