fixed door locking unlocking window not dropping problems

[Jinster]

There have been a few people having trouble with the door locking mechanism. I have just fixed problems with both of my door lock mechanisms in the last few days. Here is my summary for anyone who have similar problems in the future.

My symptoms:

driver door would lock and then automatically unlock; passenger door can only be locked by triple turning the key; driver side window would not stay dropped with the door open; the car (in terms of the dome light etc) doesn't think the driver's door is open even though it is

My problems:

driver side door lock mechanism: bad solder joints inside the door lock assembly - twisting the wire connector would erratically fix the problem of the window not dropping

passenger side door lock mechanism: two broken wires going to the lock mechanism

Primary Solutions:

driver side door: secure the wire harness with multiple cable ties to force the broken solder joints into contact; or you can resolder the contact points

passenger side: broken wires joined with joiners

Root cause:

On both sides, a plastic wire holder that holds the wiring loom to the door came lose over time due to plastic deterioration. On the driver's side, this resulted in excessive weight of the wires burdening the connector, which in turn burdens the solder joints inside the DLM. On the passenger side, the lose wires were caught by the window going down, the window sliced the wires in half.

Root fix:

secure the wires going to the door lock mechanisms with cable ties

Some suggestions:

A lot of people (workshops especially) suggests fixing the problems with DLM by replacing the DLM, which costs hundreds. Based on my (limited) experience, I think the problem is frequently the wiring loom's weight pulling off the solder points on the connector of the DLM, which should be an easy fix for all who has basic soldering skills. The weight of the wiring loom is supposed to be alleviated by the plastic tabs - but they fail and come lose over time.

Edited November 12, 2010 by Loren
removed whitespace

[Jinster]

More fixes for those who might search the forum with DLM problems:

The cable tie solution was temporary. After a couple of weeks, they became loose and the window not courtesy dropping problem were intermittent again. So I decided to fix this by re soldering those 8 pins in the DLM.

That was my intention. But I decided to try a "blind re-soldering" solution: basically, the pins are visible from outside through the socket on the DLM. The actual solder joints are inside the DLM. So instead of opening the entire DLM assembly to see the 8 solder joints and re-solder them directly under vision, I decided to try to melt the solder by applying heat to the pins with the soldering iron, taking care not to touch any of the plastic parts. After about 15 seconds of heat, I removed the soldering iron, allowing the pin/solder joint to cool. This way, you don't have to open the DLM, which saves a lot of time.

Those with some soldering experience would know that heat would get transferred down the metal pins to the solder joint anyway so you don't have to apply heat to the solder joint directly. And the solder would re-solidify within seconds of removing the soldering iron. The tricky bit here is to make sure that within those seconds before the solder re-solidified, the solder doesn't separate from the circuit board. This usually doesn't happen unless the pin/circuit board moves.

The challenge is of course you can't actually see the solder joints melt and re-solidify with this method. Some soldering experience and faith is required to get a "feel" for the situation.

Anyway, it worked. No more intermittent window problems!

Just to be clear though, this trick should only be attempted if you fully intend on opening the DLM if it doesn't work. Because the solder joint may separate completely if you weren't lucky with the "blind" re-soldering technique. And if it separates completely, you probably can't fix it with the cable tie technique.

Edited December 2, 2010 by Jinster

[Jinster]

wires to the door lock mechanism, sliced in half by the window when it went down:

[Jinster]

Pic of the wire harness that goes to the DLM - the dangling wires eventually pull the pins that supply that connector loose (the pins get pulled off the solder points on the circuit board); you can test yours by giving the connector a little wiggle - if the wiggling causes your window to drop down and go up, then one/some of your pins on the circuit board are de-soldered (likely) or the connector is loose (unlikely).

Second pic and the temporary cable tie solution that holds the hold complex in a tight non-mobile position to try to force the pins (which can't be see unless you open the door lock assembly itself) to contact the circuit board. This solution didn't last long. Re-soldering was the only way (holding up thus far).

[amegarth]

I had the exact same problem as described below. After removing the Door Lock Mechanism I took it apart (took pictures of how it was before disassembly)

I had the same cracked solder joint as shown. I resoldered all 6 connections and reassembled the unit, tested by plugging in and then reinstalled. The door lock/window mechanism is working as it was designed.

I copied this post from Pelican Boxster forum.

 

 

SOLUTION for the Doorlock failure before you buy new mechanism

After posting about my windows doing the usual popping up and down, I was planning to replace my door latch mechanisms, as this is the solution everyone has posted here.
Once I took the bad one out of the driver's door and still attached to power, I noticed, if you twist or move the harness that the latch would work. I thought at first it was bad contacts, but it wasn't.

I decided to see what really happens.
Of course this is not necessarily what happens to all out there...

I spent an extra few minutes to see where the failure was.
If you remove the 8 Torx screws that hold the cover on the translucent part of the mechanism, the unit comes apart nicely.(6 x T10s on the face, 1 T10 on the edge, and the 1 T20 on the side). Also remove the brass spring on the face (not sprung very tightly).
Inside, you find a couple of plastic gears and a circuit board. (don' worry, nothing will pop out or get lost)
Remove the circuit board and check the solder points where the harness attaches.
On both of my doors, the only solder that had a tiny hairline crack in it was the circuit that leads to the micro switches. 
Simply soldered the one contact and all is as good as new.

I believe the problem is with the repeated closing of the doors, as the solder joint on this spot on the circuit board isn't supported by anything. So every time the door is slammed and the wire wiggles, it torques the joints.

I didn't have to spend $320 for 2 new mechanisms 

     Here is a photo of the circuit board after removing it from the cover and turning it over.

You can clearly see the faulty connection on the solder (bottom-right of the 6).
That was enough to cause the failure.