Electrical OEM Door Lock Actuator Internals/Rebuild?

I'm aware of the jrichker's door lock actuator mod which seems like a more permanent solution, but I have a seized actuator I just took off of a friends car and figured I should cut it open and see how it works and thought I would document it since it was going to end up in the trash otherwise!

I cut it along the bottom near the plug with a hacksaw and gently pried it open with a screwdriver which was apparently the spot to cut it open. I then set it in a vise and pressed out the internals by setting the cut open end on one side at a slight angle then pressing against the top piece where your door lock hooks into (opposite of the connector). This pressed out surprisingly easily though I did have to gently grip the opposite end with a vise to finish pulling.

Looks like there are 2 spring tensioned brushes coming in from the connector that contact the center winding assembly. Definitely water intrusion in the actuator from the buildup all around the internals, I was able to clean up most of it.



After cleaning (QD Electronics cleaner and some brushes, and a screwdriver to gently scrape out the inside of the case where there was some debris magnetically attached).





Still need to dig out the multimeter and check the winding, doubtful there is a spec for resistance but can at least find out if there's any sort of break.

Anyone think this is worth trying to rebuild or just a waste of time? I have an LMR unit in my car at the moment and it's pretty weak so thought it could maybe be a fun project, not sure on the best way to reattach after cutting though! Suggestions and advice are welcome, also if it looks like I missed anything please let me know!

Noobz347 said:

I dunno. What are replacement units going for these days?

Click to expand...

The replacements are pretty cheap (under $20 I believe) but from what I understand they're all the same weak junk. Mine (LMR aftermarket one) will move the locks up and down fully only with the engine running and even then you have to hold the button for longer than you ever did with the factory ones. Unfortunately makes my keyfob effectively useless on that side so I have to just push the lock down on the way out and use the key to open the door on that side on the way back in.

I do wish they would just fix the aftermarket ones I think that's why the modded ones jrichker did a writeup on are so popular

Unfortunately quick follow up, looks my connector is actually shot (think it fried that chip as there's a lot of rust down underneath it), I can only get continuity through one side and it's too brittle to disassemble. I might try to cut the LMR actuator and poach the connector off of it later and keep the winding and body from this one and see how that works.

Either way, I'm going to document re-assembly even if only for myself for later since it's fresh in my head at the moment.

Step 1: Place the coil body into the connector housing, there's a small hole at the bottom that should line up with the post, then GENTLY clamp it into a vise just to keep it in place while you reinstall the brushes.



Step 2: You can either pry out the longer arm of the spring (left of the screwdriver here) to fully disengage the brush tension spring, or do what I did and just pry back on the small spring enough to slip the brush in and then release it. Ensure the spring contacts the bottom of the V shaped slot on the brush.

(Where I pried)


Open it enough to drop the brush in with the V shaped side facing towards you


Drop the brush in and slowly release tension and remove your screwdriver, it should fall into the V slot on the brush on its own but if not a slight poke with the screwdriver on the spring should help it get seated.



Repeat for the other side, then you can carefully remove from the vise (make sure to keep both pieces pushed together, they will separate if you don't) and rotate the coil to ensure both brushes are contacting properly. If you spin it at this point and get any binding on the brushes it is most likely just due to the housing not being on to keep the coil perfectly centered.

Finally, slide the metal body over by hand and should have a full "assembly" (still not sure on re-attaching the case, just a ton of RTV? LOL).

Hopefully this is able to help someone else at some point. The NOS OEM actuators, including the non-mustang ones where you swap the arm over from your mustang one, are starting to dry up on eBay so I wanted to try to pivot from buying and try rebuilding but accepting defeat for the moment until it's not over 100 out and I can pull my LMR actuator.