Door locks not working

Fireguyfire

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The door locks on my 1970 300 convertible aren’t working on either door.
The key turns the tumbler back and forth, and if you pull up or ouch down on the inside lock knobs they move, but not far enough to actuate the lock.
I pulled out the entire passenger latch system and ran it through my parts washer, then I flushed it through with WD40, then I dried it and lubed it in the recommended locations in the manual with lubriplate.
After reassembling the entire latch/lock system back in the door, the latch still operates perfectly and the locks don’t work.
Can anyone suggest what might be my issue? I’d love to get both the key locks and interior lock knobs functioning.
 

Fireguyfire

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I’ve got the door panels off and the plastic lock knobs off so it’s just the threaded Rod so that everything can move freely.
 

Power75

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Again hopefully not too obvious, but does the car have power door locks? My 69 does and the locks don't go down like a standard door lock would. Ignore this if just way out to lunch.
 

CBODY67

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Agreed, if the car has power door locks, the lock rod will feel different than if the car has normal door locks. With power locks, the rod pushes down on a switch to actuate the lock solenoid to lock the door(s). The switch runs the lock solenoid that then locks and unlocks the latch. I believe there is also an electric switch on the lh lock cyl which locks/unlocks the car via ONE key cyl?

On the power door lock cars, the old solenoids can get gunked/corroded internally. I seem to recall that you can partially disassemble the solenoid and spray WD-40 into it to free-up the solenoid to move freely again. Or update to the 1980s-style power lock actuator.

On manual lock cars, the lock rod attaches directly to the latch mechanism.

Just some recollections,
CBODY67
 

bigmoparjeff

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I don't lock my cars, so I'm having trouble remembering for sure, but I believe that on pre-1971 cars, the doors can't be locked if they are open. The only way to lock the door is with the key, when the door is closed.

If you had one door that wasn't working, it would likely be a bad latch, but it seems unlikely that both door latches would fail in the same way.

I've never had a problem with the '65-'73 latches that couldn't be solved with cleaning and lubricating.

Jeff
 
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