This instructiable details how to repair a Mini cooper door lock actuator. I did this to my 2003 mini cooper s. I was sick of reading about the countless number of people who have been forced to replace this poorly designed component with a new one ($130) because BMW made them "non-serviceable". This unit IS SERVICEABLE - if you are clever enough ;)

I would also like to thank the guys over @ NAM (northamericanmotoring.com).


Step 1: Are you sure you have a broken unit?

Confirm that in fact you do have a bad door lock actuator. Check [1] fuses [2] other door locks functionality [3] wiring harness [4] battery in your keyfob.

get your tools ready. I used torx, flat head screw drivers, pin, acetone, multimeter, DC-power supply.


<p>THANK YOU! I would never have tried this without your tutorial (with pictures)... and I would never have spend $130 to deal with the fact that the driver's side door would not unlock without the key in the lock. We have dealt with this problem for years! Now the dash button and the remote fob unlock the driver's door. It did take me the better part of 5 hours on a Sunday. I took lots of photos that I would love to share with anyone attempting this. These include the angle you need to position the actuator in to remove it from the door (took me about 10 minutes to figure that one out), and detailed pictures of the actuator and motors during disassembly.</p><p>Tips:</p><p>1) the &quot;compression&quot; washer over the pin is a real b*tch to get off. I used an engraving tool on a dremel to make a small slit in the washer so that I could pry it off. However, the washer actually cracked on the opposite side and was useless. This pin is pretty important for holding the side of the actuator against the bottom, so I had to run out to HomeDepot and pick up a #10 countersunk (flat head) bolt (#10-32 x 1&quot;) and nut to replace the pin/washer.</p><p>2) I tried using shims, but several of the white plastic clips broke (the plastic is very brittle). Turns out it doesn't really matter, the pin and 4 torx screws hold it together very well. </p><p>3) I used a product called Electro-wash by chemtronics, which is a spray for electronics cleaning on the motor. I also used a brass bristle brush, and a round nylon brush on a dremel. Be very careful/gentle when cleaning the commutators (the three copper plates around the shaft of the motor) - at their base is the very fine wiring the leads around the armature of the motor. If you scrape a wire loose the whole motor is toast.</p><p>4) I used a caliper to measure the shaft of the motor (above and below the commutator to determine the hole size to drill for the washers. I believe the two holes I had to drill were 0.1285&quot; (#30 drill) and 0.1015&quot; (#38 drill). It helps to drill the hole first and then cut out the plastic around it. </p><p>5) After you put everything back together, if you plug the actuator back into your car before re-attaching everything to test it, be sure to push down the little button in the corner of the actuator. This tricks the actuator into thinking the car door is closed and will allow the actuator to lock/unlock the mechanism. If you don't push the button, the actuator won't function, and you'll think you put it together wrong and will tear it apart, again. Maybe twice. Ask me how I know.</p><p>6) give yourself plenty of time. I started this around 1pm and finished around 6pm, with a trip to HomeDepot in the middle. I would have been done a half-hour sooner if I didn't have to go out to get the bolt/nut to replace the pin/washer, and another hour sooner if I didn't think I assembled everything wrong when I was testing it and tore-it all apart again. Reassembly went very quickly. </p>
<p>I have followed this tutorial with great results. I am sharing this image that will make putting the actuator together a little easier and a few notes I think might be helpful to others.<br><br>1) The bottom white plastic piece takes a lot of force to get it separated from the latch. Three white pins keep it in place, pry the metal plate to lift it so the pins get out of the holes (step 11 of tutorial). The white plastic clips are not very important, except for the one that is next to switch (top right of step 13 image)<br><br>2)I found the plastic washer to be the problem since in both motors was melted, you can make it out of cardboard and put a dab of motor oil to place it in position and keep it lubed. Clean the motor with contact cleaner, The rotor contacts must also be cleaned with sand paper (1000 grit). There are 3 contacts there and all must have a clean gap between them. There must be no trace there of the melted plastic, this will make the brushes of the motors skip produce sparks and heat the contacts more than normal. Before you assemble the motor, make sure the brushes are not angled in towards the center too much (they should be parallel to each other once the rotor is in), Failing to do this will result in sparks and overheating. When put properly, it will spark during test but after a few turns sparks will be reduce if at all present.<br><br>3)You can test the motors placed on the white bottom piece by connecting the harness. Keep the switch described on step 1 here pressed while testing it. This tells the computer the door is closed. The motor in &quot;horizontal position&quot; (damaged) is the one that moves the unlock pin of the door up. The motor that sits at an angle (shown at the top on step 13 image) works to both lock and unlock. When you press the unlock button on the remote only this motor should spin, if you press the unlock button then both of the motors should spin, only this time the one at an angle will do it in the opposite direction. When everything is assembled both motors should work to lock and unlock since the two switches on the top left of step 13 image will be read. This switches are pressed when turning the key to lock or unlock manually, one reads the key when turned to the left and the other one when turned to the right.<br><br>4)If your motor is plain dead, I found another tutorial that shows a motor that works. The Mabuchi FC-280PC-22125 found on bay for around $9 a pair (make sure to get the 20mm round shaft). I don't know if I am allowed to paste a link here, msg me if needed. Both motors in this actuator are the same, but the worm gear is not. Replacing the motor will require the removal of the gears anyway. When in place, the polarity of one motor is reversed so they turn in the opposite way to each other when needed. Again, replacing the motors will need more actions like cutting the shafts and reinserting the worm gear.</p>
Hi. I can unlock with the key in the door but not with the keyless entry buttons . Is this caused by the door lock actuator?
<p>it can be your key battery. can be replaced. test that first</p>
Well, maybe it is caused by the door lock actuators maybe it is not caused by the door lock actuator. You need to test other variables. Did someone writing instructable comments go for a swim with their key in their pocket?
What are the other variables ? If you dont mind giving me a brief explanation
The keyless entry button only unlocks thr gas tank cap. Also the lock switch on the master control switch doesnt unlock the doors either
The keyless entry button only unlocks thr gas tank cap. Also the lock switch on the master control switch doesnt unlock the doors either
<p>Awesome -- so glad this helped :) </p>
<p>Repair of any part of these reputed cars is too tough and <br>risky.Recently,one of my friend Mini Cooper car electric door lock <br>actuator has the same problem.He gonna tried himself and after 15 days <br>try he finally failed and the door didnt opened again. Then continuing <br>with that is a much problematic situation which is solved by Mini cooper repair Annbour Mini cooper repair Annbour specialist or say highly trained mechanic.They also took<br> less service/repair charge than any other dealers.Finally,he too <br>clearly knew whats? the problem is that.</p>
<p>say what?</p>
What? I have a bit of difficulty understanding what you have said here. <br><br>Follow the instructions and try again? <br><br>Mine still works :)
<p>Thanks for the walk through. I was able to restore the actuator in my 2003 Cooper S.</p>
<p>That is so awesome! And advice for other people doing it? </p>
<p>That is so awesome! And advice for other people doing it? </p>
Hi,I was wondering if you knew why my new to me mini cooper clubman would have an alarm go off all night? I have read allot of things but noticed that the rear door is not locking when I lock it.
<p>You realize this is an instructable about disassembling a door-lock actuator -- right? </p><p>As the guys over at NAM -- <a href="http://www.northamericanmotoring.com/forums/" rel="nofollow">http://www.northamericanmotoring.com/forums/<br></a>They might be able to help you figure out what is going on. </p>
Yes, I do. And someone had made mention to me that the door lick on the rear swinging door might not be latching and it's making the alarm go off. It isn't. So I thought it might be one thing I could try. And thank you for the link.
Hi! I have exactly the same door lock on my land rover freelander as mini cooper and i want the motor part code or specification of motor such height width .. thanks
<p>Measure it from the photos? <br>or find an ebay seller and ask them to measure it for you. </p><p>Best of luck with the fix! </p>
<p>OK, thanks very much for you answer. I did not see sensors. Now its OK, I saw it on the 13th photo.</p><p>Based on your experience, if i remove the entire the Lock Actuator, to try to repair it within one week in my house (not having a garage), can I still close and open the door manually?</p><p>Does the removal of the locking mechanism will not permit me to close or open the door with the normal key?</p><p>Thanks</p>
<p>correct, look at the photos again.</p>
Done it, worked well getting the electrical plug out was difficult as squeezing the clips without being able to see was impossible. But once u drop the unit it's easy. I brought a used replacement from Baverian Auto parts in California $85 and the shipped it up to vancouver saved on BMWs prices took about 2 plus hours to do
<p>Hi everybody. Got an interesting question before approacing to repair my Mini Locking left door.</p><p>One month ago : Not opening function but correctly worked on closing </p><p>Last week. No opening and no closing operation.</p><p>Now, when I open and close manually with the key, the other right door , the fuel security door and the Arrow lights work as normal.</p><p>Question:</p><p>If both motor were broken, how come signal (coming from the same motor while closing or opening manually the door) is able to send signal to the central unit ?</p><p>Sorry for my bad english.</p><p>Thanks</p>
<p>look at the photos again. There are sensors that are independent of the motors... The brushes on the motors burn out -- this has nothing to do with the switches that send signals to the head unit. </p><p>based on your question, I don't think this is a good fix for you to attempt - might be too complicated. If you do it - post pictures :) </p>
<p>look at photo in sept 13. upper left hand corner. </p>
Thank you for your instructable, my 2005 mini cooper had the exact problem your door lock had. I have it back together and functioning.
<p>Thanks for the information - very useful. Like you my problem was the unlock motor. when I took it apart to repair it, the commutator surface was a mess with several fused bits on it. I think the problem with these could be the plastic washer at the top melting on to the commutator. The lock/unlock motors look the same but the brass worms are different sizes so these are not interchangeable. I looked for replacement motors but nothing obvious available. Be good if someone could find a source for these. </p>
<p>Thanks so much. I was about to tear into mine anyway since I could either fix it or replace it as Mini says, but mine had the same problem as yours and with a quick cleaning and lube, my 2003 Mini is back in service for an hour of my time. </p><p>You are 100% right about pictures of the springs. Make sure to take a few when you tear it apart. Thank God you had yours up so I can see how the one spring fit back in. Otherwise I'd still be messing with it.</p>
wawoo; look at the cheap plastic end motor they use. exactly like the motors we find in children toys that break easily. I cannot believe car makers go so low to save cost. At least they should have put a full metal body motor for longer life. Thanks to poster, good subject though.
Thanks, you did a realy good instructable. with your help i fix my lock on my 2005 mini. <br>but on my case all 3 coper contact were appart. so i carefuly unsold the wire and put a new one from another small 12 v motor that i use in slot car racing .wen you do that the timing betewen the 3 coper blade is important so refer to small electric motor timing to alling propely with the magnet and carbon brush.
Thanks for the post. I followed your instructions and repaired my 2004 Mini Cooper door lock actuator. I would just say that it is important to note the position of the gears and motors as you are disassembling. I didn't and had to take it apart a second time after it didn't function after the first test. When you are actuating those little motors up and down, you can get lost as to which way it should be. <br> <br>It has been at least 2 months since I repaired mine, and it is still functioning.
It has been about a month and everything is still working well!
Nice! My rear door lock actuators on my Mazda 5 are all but dead, but I was dreading taking them apart. I'm sure all door lock actuators have a lot in common, so I'm sure this will be helpful when I decide to tackle it. <br><br>Where is a good place to buy the little motors, if necessary?
Its been my (limited) experience that generally you can repair most electric motors. As for a replacement - I woudl look to source a motor from another actuator - it is very tight in those cases and hacking one to fit would not be easy. Good luck!

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