How to change a door lock mechanism

Opening the passenger door on my MGF 1.8i failed to activate the courtesy lights – not that big a deal but it also means that the alarm, if set, is not triggered. The fault lies in a micro switch within the door lock mechanism which in effect is a sealed unit so the solution is to replace the mechanism and fortunately used parts are available for under £20 (make sure you get the right one – driver’s & passenger door parts are ‘handed’ so are not interchangeable and you do need one from a car with central locking).

The mechanism is quite a complicated bit of kit. It has an electrical connection (5 wires in a plug) and 3 mechanical connections – one each for the external handle, the internal handle and the door pin. The mechanical connections are shown here




The internal handle fittings are easier to see when the mechanism is rotated through 90 degrees as fitted to the passenger door (with the front of the car to the right)



To remove the old fitting, first remove the door card then carefully peel forward the clear plastic liner that you should have fitted to prevent the door card getting damp. Work with the door open. With the fitting in-situ undo the external handle clip first.
This shows the clip….you need to pull it off the rod which will then pop-out of the centre of the red clip.


After that I found it easiest to disconnect the electrical plug by pushing the fir tree fitting in to the door and pulling the plug. Next, undo the 3 torx T25 ‘bolts’ that hold the mechanism in place:


With the unit loose, undo the internal handle at the mechanism end. The outer cable is held in the clip and the working end has an ‘s’ bend which you can wiggle out. This shows the cable after removal.





This shows the clip and the hole for the ‘s’ fitting.

Next you remove the whole unit complete with the door pin by dropping it down and more wiggling. Note where the door pin exits the door normally before you do this! This then gives you the old unit with door pin fitted thus:



Wiggle out the door pin.
As always, fitting is the reverse! Fit the door pin to your new unit. Wiggle the whole lot back in to the door with the door pin emerging from its correct hole. At this point it is best to refit the external handle connection, then the internal handle connection then offer-up the fitting and refit the 3 torx bolts. Finally, re-connect the electrics and push the fir tree connector back through its hole.

Re-fit the plastic liner (sellotape) then the door card. Job done!

Nice one!

Pefect how to! Thanks buddy!

great piece of work - extremely helpful - managed to do the lock in a few minutes

I've just used this How To on the MK1 F's passenger door lock. It only took a few mins and was very straightforward thanks to these good instructions. In my case it was to resolve a problem with the lock 'machine gunning' the PO said had been a problem for 10 years. Silent now other than the reassuring single thud on locking or unlocking.

I found it tricky to balance the top locking pin linkage correctly so that it would go upwards through the correct slot in the metalwork at the top whilst i was having to hold the lock in the right place and also get one of the fixing bolts in.
To avoid the need to call on someone to help with a 3rd hand, i lowered a long bit of string through the lock pin's intended slot, tied it round the lock pin linkage and hauled this up so the pin was then in the right place. Holding the string in the same hand i was using the hold the lock mechanism in place then left the other hand free to put the bolts in and it was done right first time in seconds.

Whilst in there I opted to disable the Superlock which can be notoriously troublesome. This just involves cutting the Brown/Prink striped wire. Now I have piece of mind that the passenger door can never be jammed permanently locked as has sadly happened to several owners.

This mod does not adversely affect the normal central locking or security and the Superlock feature is quite pointless on a convertible.

Hello, I intend to replace the LH (driver’s side) door lock on my LHD 03 TF with Central Locking, as it has started to machine-gun on some occasions.

Someone can please confirm that FQJ102292PMA is the ref I need?
I am a bit confused 

If you have fob for central locking for 2003 MG TF LHD car FQJ102292PMA is door lock for LH drivers door 

Thanks so much, Roverlike  

I found this thread interesting as I'm just on with this job now. Thank you for the information.
I have the same issues as above with the nearside door, so I have removed the door lock mechanism with the intention of replacing it, but currently struggling to find a decent s/h one. It also looks like someone has been in there before as the mechanism does not look original; so more than likely a s/h unit will either have the same fault or will have at some point anyway probably the day after the door cards get put back on.
Has anyone stripped the door lock to find out what has worn or broken? and does the Chinese MGTF have the same arrangement and wiring? 
My thinking is that the newer TF,s parts wouldn't be as worn out as my 2004. 
Regards.
Gary.

Just found some more thorough information from Delbourt labelled "Super locking how to defeat".
This thread has some very useful information and images of the lock cases stripped down showing the components.
I think the way forward is to disable the super locking ability.
Regards.

Wow, what a job I have had today,....decided to take the door lock casing apart to see if there was anything in there that was broken, worn or not connected, but everything looked fine.
I cleaned the excess grease off the parts then after reading much of the information regarding "super locking" and how to disable it I chose to de solder the pink wire on the mechanism (neither of my locks on the Tf have a brown and pink wire). I think this was my first mistake!
After reassembly I fitted the lock back on to the door, reconnected the connector and tested it with the door open, all seemed ok. I then unlocked with the fob and closed the door,....then locked it with one press of the fob.
However I then pressed the fob to unlock it and nothing happened, tried the process again and no response. Two hours later after several attempts trying to open the door in a non destructive way I admitted defeat. 
Eventually I took a hammer and chisel to the mechanism and smashed it to bits, luckily the door cards were off anyway. I got the door open!
Had a coffee, gathered my thoughts to think what I had done wrong, and decided it was removing that pink wire. What else could it have been I was quite diligent putting the lock components all back together correctly and even if the micro switches had totally packed up I should have been able to force the catch to open. 
I've managed to order a s/h replacement so I will see how that goes.
Regards,....Gary
 

AH! I've been looking into this problem on and off for a couple of years and follow all of this with great interest in the hope of one day fixing it! One thing I have noticed is that the wiring attached to the lock itself doesn't use the same colours as the loom wire on the other side of the lock connector (Confusing, I know!). I am guessing that the brown/pink wire is the loom colour for the superlock (The wiring diagram would confirm this).