[Vctr]

Have a problem with my central lock on T4
When I lock driver's door with a key, it unlocks, when I lock with remote, it doesn't lock but all other doors are locking and unlocking again.
So it looks like a problem in wire (probably the wire which sends a signal to lock the door), but I don't know which color wire is it. Can't find diagrams.
The actuator is working fine (goes there and back). So the only thing which I can't force it to do is to lock when it's connected to the car (but I can "lock" it when I unplug it and connect to power source).

Does someone have some tips or at least diagram of the lock wire?

Can I bridge the connector somehow and check if the problem is in the wiring?

 

[Vctr]

Checked conector with multimeter, and the yellow cable (which should lock) doesn't have voltage. So then it's the wire or connector.

 

[Vctr]

Checked the wiring from fuse box, and found out that yellow wire should not have power when lock is open, when it locked, then white cable doesn't have power, which makes sense.
So then wires are fine.
Thinking about swapping actuators from another door to be sure that the problem not in the actuator.

 

[Vctr]

After a few tests with swapping actuators, the problem became more complicated.

When I change actuators, problem is the same => actuators are fine 100%

When I disconnect actuator from the driver door => all doors can be locked and unlocked with remote, and when I lock manually from passenger side, all other doors locking. So they work fine.

When I disconnect actuator from passenger door => I can't lock with remote (motor on driver door doesn't pull down), and other doors locking and immediately unlocking (I guess because get signal that one door is not locked), BUT if I lock it manually, then I all other doors can be locked with remote.



The easiest solution is to disconnect driver door actuator and then I can lock the car (manually driver door and remote for others), otherwise I can't lock it at all (because it unlocks even when I lock it manually).

But I wanna find an answer to this problem. Any tips?

 

[Vctr]

Few more tests with actuator connectors:

Driver door connector always shows 12V on "Open" wire (and this is probably why it keeps unlocking)
doesn't show 12V on "Close" wire when I close door with remote (which probably means a problem in the wire, have to check it again)

Checked the same on the passenger door, and that connector sends 12V to "open" or "close" only when I open/close with remote

I'm not sure if it should be the same on both doors though. Maybe with diagrams would be easier to understand. Or with test on the other T4 with working lock. YouTube has no videos about wiring.

 

[Vctr]

Did one more test with a multimeter on the wire and found out that there is OL on yellow cable (which responsible for locking).
So this can be the answer, but it's raining outside and have to wait when it will stop, then check spot on the wire between a car and the door, where usually a lot of problems.

 

[Vctr]

Problem fixed, it was broken wire in the problem zone between door and body.

 

[Or_GazM]

As 99% of the time!

How many "bad" wires did you find in the belows?

I only found 7 in my when I last looked.

 

[Vctr]

As 99% of the time!

How many "bad" wires did you find in the belows?

I only found 7 in my when I last looked.

1 was broken and few were damaged, and a lot of tape from the previous owner. Have to fix it properly one day and put some good protection.

 

[Or_GazM]

Cut and splice an extra 5cm into each one.
The loom pulls too tight....VW saving 1 Nok per door!!!!
Solder and heatshrink is the best way...crimps are not flexible enough.