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Discussion Starter · #1 ·
I'm working on a '99 2500 Suburban. My issue is when I push the power lock button, in the lock or unlock direction. I only get 3 of the 5 doors that will lock and unlock. I can see the passengers door lock moving about half way with either function. If I push the button 3-5 times to lock or unlock, the system acts like it is loosing power and will no longer lock any of the doors. I can still hear the locking relay clicking, just no power getting out to the actuators. If I wait about 5 minutes, it will work fine for 3-5 pushes again, then just relay clicking. I get the same results using the key fob. I have exchanged the lock relay, and the drivers side power lock button from my parts vehicle and have the same results. Where do I look next?
 

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Have you tried cleaning and lubing the lock mechanism? After 18 years they may be a bit sticky. It wouldn't hurt to do all the locks. While you have the doors apart do the windows, too. I've had good luck with white lithium spray lube.

Ted
 

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Discussion Starter · #3 ·
Forgot to mention that, I did lube everything I could find related to the lock mechanisms in all 5 doors. I didn't expect it to help because of what seems like the lack of voltage to the actuators. On my weekend work day for the Suburban I will test voltage at the actuator to see if there is actually a voltage drop with additional pushes on the unlock button.
 
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Sounds like a plan. When/if you do lube them you want a lube that won't dry out.

Ted
 

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I know this is an old thread... but were you able to resolve this?
I'm having similar issues - both front doors will power-lock, but the two rear doors & hatch won't - but you can hear them trying/clicking.
 

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So when i first got my Burb the drivers door lock didnt always work right. I couldnt figure it out for a long time but what it turned out to be was a rivet holding one of the parts to the door had sheared off, but nothing looked broken. By chance i saw the rest of the rivot in the door while changing a door speaker or something i csnt remember. I replaced it with a big self taping screw and holy **** it worked! Have a close look at everything, compare them to the other doors. Man i hate working inside doors but i would take all the skins off and plug the switchs back in for troubleshooting.

What's happening, at least in my situation, was the actuator and all the wiring ect worked perfectly but with that missing rivot there was to much slop in the rods and so the lock itself would not move much if at all. Sorry that i can't remember where this rivot was missing though.

Al
 

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Discussion Starter · #7 ·
I haven’t figured out my problem yet. Weather’s been too cold and crappy to want to be outside working on it. My plan is to change all five actuators to brand new and see if that will take care of the flow of electricity through the entire system.
 

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It comes down to a poor door lock actuator ground. After 18 years, the ground can also fail.

You have 2 proper methods of repair, one drill out the old actuator mounting rivets and install dealership type rivets with the mandatory use of a air / hydraulic rivet gun.

Or get a bunch of 1/4 inch bolts with locking nuts and star washers and mount it that way hoping for a good actuator ground.
 

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FYI - while waiting for my new door actuators to arrive I decided to replace the door lock relays to see if it would make any difference. All 3 doors (both rear & tailgate) began working again! I just wished I had read about the relays before I ordered the actuators. Needless to say, I immediately returned the actuators upon delivery (of course I had to eat the return shipping costs). But in case anyone else runs into this, it's the two 8867 relays located in the driver-side fuse box.

(disregard the 2 red pigtails coming from the relays... dunno why they were there so I yanked them out as they weren't connected to anything)
 

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cfanto,

Please remove the 2 red wires under the relays. Whomever installed those wires attempted to do a relay bypass method. With new relays, there is no need for them.

By the way, you had at one time little rodents playing around the fuse panel. Hope that didn't cause some problems in the wire harness???
 

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Discussion Starter · #11 ·
What year are you working on? That looks nothing like my drivers side fuse box and my lock relay is under the dash right above the gas pedal.
 

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I have an 09 Silverado that is having a similar issue. JackE, you said that the relay is by the gas pedal? Do you have a picture of that location? Did you ever figure out your issue? I'm trying to figure out if I need to replace the relay or the driver door lock/latch actuator.
 

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Discussion Starter · #14 ·
I was working on a '99, completely different animal than your '09. I have no idea where the relay is on yours. I didn't find the solution but my plan was to make sure the ground was clean on each actuator before I just replaced all of them. My ultimate solution for that problem and multiple other little issues was to trade the Suburban for a newer Escalade. Haven't regretted the decision yet!
 

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I was working on a '99, completely different animal than your '09. I have no idea where the relay is on yours. I didn't find the solution but my plan was to make sure the ground was clean on each actuator before I just replaced all of them. My ultimate solution for that problem and multiple other little issues was to trade the Suburban for a newer Escalade. Haven't regretted the decision yet!
I wish I could do that... New vehicles are so expensive these days! Thanks!
 

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Discussion Starter · #16 ·
Due to the good fortune of my son and his misfortune with a deer, I got his Escalade with some minor cosmetic front end damage, and he got my Suburban to sell and a fat insurance check on the Escalade. There's no way I will be taking on a payment this close to retirement!
 
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