Drivers door will not unlock all the sudden.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

duece1951

Member
Joined
Oct 7, 2023
Posts
47
Reaction score
45
Location
Fort Myers, FL
First Name
thomas
Truck Year
1984
Truck Model
GMC C1500
Engine Size
305
Put truck together yesterday. Drivers door will not unlock, it’s not the key cylinder or actuator. It physically will not unlock pulling up the lock. I have the door apart and the cylinder out. Nothing seems to be blocking it. The actuator is new. Worked fine until til I painted it. But even then it locked and unlocked after and during. Any idea what happened?
 

legopnuematic

Licensed Junk Dealer
Supporting Member
Joined
Oct 27, 2016
Posts
5,145
Reaction score
19,161
Location
MO
First Name
Spencer
Truck Year
1971, 1̶9̶7̶4, 1976, 1979,1̶9̶8̶5, 2002
Truck Model
Dart Swinger, Sierra 10, C10 Cheyenne, C10 Big Ten, Silverado 10, Ram 2500
Engine Size
225/6, 350 c.i., 350 c.i., 5.9l Cummins
Have you tried pushing the button on the exterior door handle first, then attempt to unlock?

My 76 is that way. Don’t know why (guessing wear in the various linkages).
 

Chevy 88

Full Access Member
Joined
Mar 28, 2025
Posts
783
Reaction score
792
Location
Canada
First Name
f7t6
Truck Year
1988
Truck Model
GMC
Engine Size
350
Put truck together yesterday. Drivers door will not unlock, it’s not the key cylinder or actuator. It physically will not unlock pulling up the lock. I have the door apart and the cylinder out. Nothing seems to be blocking it. The actuator is new. Worked fine until til I painted it. But even then it locked and unlocked after and during. Any idea what happened?


You could try stripping all the paint back off the truck, to see if that helps. I mean, it worked before you painted it, right?

Ha.

Seriously though, I would take the door panel off and reach inside with one hand to grab the lock knob rod. And then push up and down on the lock nob with the other hand. Then follow that rod to the next part, and wiggle the lock nob, and so on. Somewhere the free play stops. That's likely the culprit. Maybe some part of the system got pinched between something. Or a rod came off and got the end stuck in a screw hole or in some other spot. Just got to trace the problem by hand.
 

stvaughn

Full Access Member
Joined
Feb 7, 2025
Posts
72
Reaction score
106
Location
West Tennessee
First Name
Steve
Truck Year
1990
Truck Model
V1500
Engine Size
350
Put truck together yesterday. Drivers door will not unlock, it’s not the key cylinder or actuator. It physically will not unlock pulling up the lock. I have the door apart and the cylinder out. Nothing seems to be blocking it. The actuator is new. Worked fine until til I painted it. But even then it locked and unlocked after and during. Any idea what happened?

Duece, have you solved your problem yet? I’m having the same problem on two doors. I think I have found the cause but not sure.

Steve
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
13,906
Reaction score
23,758
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Have you tried pushing the button on the exterior door handle first, then attempt to unlock?

My 76 is that way. Don’t know why (guessing wear in the various linkages).
^^^^^^THIS^^^^^^
Mine does the same. A push of the button and it unlocks
 

Sad Sack

Supporting Member
Supporting Member
Joined
Sep 3, 2024
Posts
2,640
Reaction score
5,505
Location
Nebraska
First Name
Goober
Truck Year
1985
Truck Model
C15
Engine Size
305
Are the handles original or aftermarket? I’ve heard of some aftermarket ones having issues.
 

bucket

Super Moderator
Staff member
Moderator
Joined
Aug 3, 2010
Posts
35,125
Reaction score
43,715
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
^^^^^^THIS^^^^^^
Mine does the same. A push of the button and it unlocks

Yep. Experienced the same issue on a couple of mine in the past. Oddly enough, they both quit doing it at some point. They somehow repaired themselves.
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
13,906
Reaction score
23,758
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Yep. Experienced the same issue on a couple of mine in the past. Oddly enough, they both quit doing it at some point. They somehow repaired themselves.
Mine works fine if it's raining, but when things dry out, push the button again. Whenever I get in the doors I'll apply some grease and see if that helps or fixes it
 

stvaughn

Full Access Member
Joined
Feb 7, 2025
Posts
72
Reaction score
106
Location
West Tennessee
First Name
Steve
Truck Year
1990
Truck Model
V1500
Engine Size
350
The aftermarket handles that the PO installed on my 1990 suburban have o- rings surrounding the plastic push button. The o-rings break and cause the push button to not retract all the way which jams up the latch mechanism. If anyone has aftermarket handles that work properly please post up and tell us where you bought them.

Steve
 

texasmike

Full Access Member
Joined
Sep 18, 2018
Posts
314
Reaction score
239
Location
Conroe Texas
First Name
Mike
Truck Year
1984
Truck Model
C10
Engine Size
305
Hey Steve,
You saved my bacon and a lot of time, money and grief with your post and I thank you very much. I had noticed a tiny bit of rubber sticking out of the bottom of the handle below the button so after reading your message, I went outside and pulled out on the black button and voila, the door lock pull came right up. PTL!! This was an aftermarket handle which was put on a little over 5-1/2 years and 12k miles ago. The chrome looks great and I wonder if that o-ring can be replaced?
 

stvaughn

Full Access Member
Joined
Feb 7, 2025
Posts
72
Reaction score
106
Location
West Tennessee
First Name
Steve
Truck Year
1990
Truck Model
V1500
Engine Size
350
FYI, for anybody and everybody that has trouble with the door latch mechanism locking up and causing a “I can’t open my door “ situation I believe that I have found the root cause of the problem.

The o-rings in the push button are a contributing factor but not the root cause.

I spent hours with my door panels off trying to determine what was causing my problem. At some point I dug out an original handle that I had and started comparing it with the new handle. That’s when I noticed that the tang on the mechanism that rotates up and down when you push in on the push button is longer on the new handle than the one on the old handle. At that point I re-installed the new handle without booking it up to the latch and saw that the tang was rubbing the inside of the door skin and would sometimes hang up. This created a situation where the lock mechanism in the latch would hang up midway in its travel and not allow the latch to unlock.

I disassembled all my brand new handles, ground enough off of the tang to allow for some clearance between the tang and the inside of the door skin and solved the problem. Picture below.

Hope this helps someone.

Steve

You must be registered for see images attach
 

saltdog

Supporting Member
Supporting Member
Joined
Aug 9, 2020
Posts
171
Reaction score
214
Location
US
First Name
Mike
Truck Year
1983
Truck Model
K20 Suburban
Engine Size
350
Does anyone know where you can buy aftermarket ones that are decent. work like original? The last ones I got were Dorman and the buttons are way looser than OEM- when you push the button there is no resistance until about halfway in. Its like they used a short spring
 

stvaughn

Full Access Member
Joined
Feb 7, 2025
Posts
72
Reaction score
106
Location
West Tennessee
First Name
Steve
Truck Year
1990
Truck Model
V1500
Engine Size
350
Does anyone know where you can buy aftermarket ones that are decent. work like original? The last ones I got were Dorman and the buttons are way looser than OEM- when you push the button there is no resistance until about halfway in. Its like they used a short spring

saltdog,

Dorman Help! are the door handles I used and after my modification they work fine.

Steve
 

duece1951

Member
Joined
Oct 7, 2023
Posts
47
Reaction score
45
Location
Fort Myers, FL
First Name
thomas
Truck Year
1984
Truck Model
GMC C1500
Engine Size
305
Duece, have you solved your problem yet? I’m having the same problem on two doors. I think I have found the cause but not sure.

Steve
I did! Took the door panel off and took a power washer and brake cleaner, sprayed the mechanism inside the door. I think I must have had something wedge into the moving parts. Keys are useable! I also moved the door striker the door lock mechanism wraps around in the door jam out slightly.
 

Forum statistics

Threads
48,414
Posts
1,066,918
Members
42,800
Latest member
wshoneybadger
Top