One of my popular posts continues to be the problems I have experienced with my power door locks on my 2004 Pontiac Vibe I purchased from hertz car sales in 2006. As the car has aged, more electrical issues show up that are just plain annoying. The latest two, in addition to the power door locks, are the heater blower motor not spinning up without banging under the dash and the servo actuator for the damper for fresh or recirculating air. The damper would go over to fresh air and just start clicking every second. Some Google searches turned up the problem as a missing tooth on one of the gears in the actuator with a possible solution of rotating the gear 180 degrees. So today I decided to tackle these three issues and ultimately had success. For the actuator, I give fair warning. It is a pain in the butt to get to without taking out the dash. The bolt head size of the screws are 7/32″ and even the smallest ratchet will have trouble getting to the screws. I went to O’Reilly Auto Parts and picked up a Ford distributor tool which is a 7/32″ socket with knob for turning it. This worked for the lower screw, but not for the top one. I ended up having a ratchet wrench that I was able to use with a socket and finger turning attachment. I bought a SAE and Metric set of these thumb turning sockets from Big Lots sometime ago and never really used them, but they saved the day on this screw. Once the actuator is out, there is a clam shell plastic cover to open. I tried to pay attention to the position of the large gear with the missing tooth as it needed to be rotated so the missing tooth is on the backside. When re-assembling the actuator, I tried to match the position of the damper interface to the same angle and used a stick to push the damper to the recirculate position when putting the actuator back in place as that was the position the damper was in when the actuator was pulled. Putting the screws back in was just as much of a pain as taking them out. If you have a mechanically inclined skinny teenager around who is also a lefty, it might be worth some pizza for their hands to take out the actuator and put it back.
On the heater blower motor, there is a little metal box with three mounting screws that needs to be unmounted to get to the motor mounting bolts. I also had to remove some plastic trim anchors to allow a little black plastic flap to move away from the bracket holding the little metal box. Then there were three screws to take out in order to drop the fan motor. These are also 7/32″ and a small ratchet should work. It did for me. Once I had it out, I used some CRC electrical cleaner and degreaser after removing some black fabric cover from some slots on the side of the motor. I sprayed some pretty significant amounts of cleaner into the motor. The resulting fluid that drained back out was a nasty black carbon color. I kept spraying the cleaner and draining the motor until it was draining pretty clear. I also removed some tape over the axle and tried to get some Tri-Flo into it. One note, the cleaner started making the rubber gasket around the blower mounts seem a little too flexible so I took off the gasket and washed it before reinstalling it on the blower mount and reinstalling the blower motor. My guess is it is possible to remove the tape and spray some cleaner into it, but have some rags below the motor to catch the run off. I would also give the cleaner a chance to evaporate before powering up the fan. Once I was done with these two fixes, I decided to go for a final fix on the passenger door power lock that has not worked in over two years.
Edit: I don’t have this car anymore and I still get hits on this post every day. Thinking about the effort it takes to do this job, I have started thinking it might be easier to just drill a hole in the plastic clam shell near the electrical contacts that need to be cleaned of the grease that has migrated from the gears to settle on these contacts, which is the cause of the problem, and keep spraying degreaser and on the contacts and draining until the grease is completely gone from this area of the mechanism. If someone tries this method, please let me know if works.
Check out my previous post for the tear down and reinstall. What I did this time was to get the actual latch/lock mechanism that has the little motor with a worm gear open and clean some electrical contacts and tighten the contacts to the little motor. Taking apart this clam shell is not for the faint of heart. There is a black plastic piece that fits around one corner that has to be removed first. Then there are three Phillips head screws that need to come off. Once the screws were out, I was able to able to eventually slide the metal latch portion off which makes getting into the clam shell easier, but not easy. The direction to slide the metal portion is away from the side that has a blue mark on one of aligning pins. At this point, I started unlatching the little clips all the way around the clam shell. There are three main portions to the inside of the latching and locking mechanism. One is the lock interface to the door key, another is the latch release that interfaces with the outside door handle and the last is the cable connections to the inside door handle and lock toggle. There are two electrical contacts on the plastic internal pieces next two the key lock interface. It is my guess that the these contacts get dirty and are part of the problem with the power door lock mechanism. So I used the electrical contact cleaner to make sure there was no grease on either the embedded silver contacts in the black clam shell or the copper protruding metal contacts from the white plastic pieces. The other electrical contacts are from the claim shell into the electric motor with worm gear. There was a chance the spring memory of the contacts in the motor may have been spread out too far, so I pressed them closer in before trying to reassemble the clam shell. This is where my trouble started. I did not note where the two metal pieces that interface with the latch and lock were in relation to the plastic piece that interfaces with the gear turned by the worm gear and the locking interface. Turns out that it is pretty easy to figure out as one metal piece has a hinge to the black plastic while the other metal piece floats above the black plastic. What this means is, the one next to the black plastic goes on the bottom of this key plastic interface and the other on top. Then the hardest part is getting all of the gear axles and a persnickety spring that provides the locking feel when the inside door lock toggle is moved manually. It will fall out of place pretty easy so I put some thick grease on it to try and hold it in place while reassembling the clam shell. Once the latch and locking mechanism was reinstalled I was pleasantly surprised to see it work. Based on past efforts this could last a day, a week, or a year.
I will admit that at one point I thought I was going to have to order the lock/latch mechanism from the dealer ($205) or start hitting the self service junk yards to find one. But bringing the clam shell and parts inside to the kitchen table and looking it over, it only took about an hour to get it back together. All in all, the three projects took about six hours to complete including the trip to the auto parts store.