You do need two people.
Mk5 golf drivers door not locking.
One operates the central lock switch on the drivers door while the other tries to open the passenger door.
How to remove vw golf mk5 door lock to repair central locking issue.
Also you can take the door panel partly loose.
9 times out of 10 there is damage to one or more of the wires that run from the door to the body.
Just something els to check while your looking at the wiring at my work we used to see alot of mk5 s with similar faults.
So can you lock the car by using the key in the drivers side door lock.
I did find one post on the mk5 golf gti forum that looked hopeful though even though ours is a match not a gti and decided it was worth a try.
Once off the wiring that enters the panel near the latch can be pulled slightly and try the lock unlock with the key.
Just unclip and pull back the rubber boot and check the wiring.
If the lock slowly started to lose power speed locking and locking or would stop working intermittently and start again the motor actuator is most likely to blame.
If one set of switches can control the windows it s likely the switch on the opposing side that needs to be replaced.
With the door open flip the latch and open it so you can see how it works.
The power windows lock unlock trunk release mirror switches and all that do not work.
Golf mk5 gttdi 2 0 nov 19 2007 3 1 on the fuse.
You will not get all the screws out.
You try and open the door at the same time as it tries to unlock.
If you look at the other doors that will open you will notice a lever on the side of the latch it will release the latch.
The windows work off the passenger side switch but not the drivers side or vice versa.
If it works will the wiring pulled slightly the wiring in the actuator will be bad.