78 Seville Rear Door Won't Unlock

[Michael Brittan CLC #2750]

The driver's side rear door of my '78 Seville has suddenly developed a bug and won't unlock.  The door is closed and neither the outside nor the inside handles will open it.  The power window operates normally.  The passenger side rear door locks and opens normally.  Does anyone have any suggestions before I undertake an expensive trip to the dealer?

[Otto Skorzeny]

I'm assuming you have manually pulled up the lock button and the handle still won't open the door.

You're probably going to have to slim Jim the door and take the interior panel off.

It sounds like the rod that connects the handle to the lock has slipped off.

[Michael Brittan CLC #2750]

Thanks for the response, Otto.  There is unfortunately no manual lock button for the rear doors on these cars.  The pushbutton on the outside door handle just depresses without actuating the opening mechanism, and the interior handle can be pulled with the same result.  So it looks as if the door locked automatically (which it does when the driver is seated and the transmission is put into "Drive"), and the solenoid is stuck or otherwise faulty.  So, it looks like someone who knows how to do it will have to wield the "slim jim" as you suggest.  Regards, Mike

[Michael Brittan CLC #2750]

I'm assuming you have manually pulled up the lock button and the handle still won't open the door.

You're probably going to have to slim Jim the door and take the interior panel off.

It sounds like the rod that connects the handle to the lock has slipped off.

Hi Otto:  I stand corrected.  I have just retrieved the car from storage, and it does in fact have a manual lock lever on the door armrest.  The lever must somehow have been actuated and the handles were disabled.  Thanks for your input.  Mike

[bcroe]

I have had this happen, when the outside handle would not fully return when released.  Then the lock cannot be unlocked.  Check it out.  Bruce Roe CLC # 14630

[Otto Skorzeny]

Wow! so no locksmith or slim jim pro needed?

I love it when things work out right!

[Michael Brittan CLC #2750]

Otto, Bruce:  Thanks for the postings.  I'm not quite out of the woods yet.  I think there may be a loose electrical connection or the door locking solenoid is faulty.  If I lock the doors with the switch on the driver's armrest, the rear door will lock, but it cannot then be unlocked electrically.   But at least the door can be opened to get at the innards.  Cheers, Mike

[Otto Skorzeny]

The Master control will lock the door but will not unlock it?

The individual door control will neither lock nor unlock, correct?

Can the individual control switch for that door be removed without taking off the door panel? I suspect contacts on that switch are probably corroded or dirty.

Take the switch off the door and see if the door will lock or unlock when you make direct connection on the terminals with a pair of pliers.

[Doug Spingelt]

I'll add my two cents worth.  There is a lever return spring in the inside of the door.  it runs horizontal in the inside of the door mechanism by the latch.  this tiny spring pushes back the lever which enguages the lockas and door handle and it gets rusty and breaks.  the lever is fairly free moving and will sometimes even retract if you are on a hill, or can wiggle the door handle a bit.  I have this issue in my 75 eldorado.  I have become good at opening the doors if someone accidentally lockes them.  I use a hanger withb the window down and just mess with it until I hit the lever return and then yeah it will open.  They look like a long spring from a retractible ball point pen. 

these springs are innexpensive to buy and I will be doing it when I replace my door covers on the inside.  somehow... 

Good luck. 

--Doug

[Michael Brittan CLC #2750]

Gents, thanks for the feedback.  I can provide update on this saga.  I eventually took the car to the dealership who has some experienced technicians.  They found the Door Lock Actuator (i.e. solenoid) to be defective.  The OEM GM part no is #22020256 good for Cadillacs from '77 - '91.  It was quoted at about $130!  Online I found a Dorman replacement part no #746-014 for about $32 with free shipping.  We'll see if this works when it arrives.  Mike