artbuc

Here is a very interesting post describing how to solve the infamous door lock actuator problem. This thread contains a link to a Ford forum which gives a good description. Apparently, there is a thermal device which limits the current to the actuator motor to keep it from burning out. This device gtes stuck in the high resistance mode preventing the actuator motor from getting enough current to operate.

Roger, you examined the motor and concluded the brushes had worn to the point of no repair. Do you remeber seeing this thermal device (resistor)?


http://www.toyotanation.com/forum/sh...d.php?t=340997

code58

Hi Art- Just got back in town last night after having been gone for 15 days. I have seen the description (and pictures) of the Ford lock w/thermal device (since I own a Ford truck) and the Lexus lock actuator assy. had nothing like that. It was simply that the the little 3 cent brushes in the $1. Chinese motor were completely worn to the point that they no longer wanted to contact the commutator with sufficient pressure to operate the motor, even though I cleaned everything up inside like new and bent the brush holders to apply more pressure to the commutator. The brushes are tiny things with the little blade on the brush simply forced through a tiny slot in the brush holder. Though the quality of the motor was decent for a Chinese made product, the design is extremely low cost and designed with the complete knowledge that it WILL have a limited life. They know that the greatest likelyhood is that most people will never cut the electrofused assy. casing apart (as well as taking the motor apart(but then they don't know me do they? ) to see the motor that powers it, or the brushes that operate that motor. I calculate that that motor probably operates a total of no more than 2 hours in it's lifetime before it expires.

sktn77a

iTrader: (2)

I recall seing a DIY post a year-or-so ago using a "slave" actuator and leaving the original Lexus actuator in place. Does anybody have any experience just replacing the Lexus actuator with an aftermarket actuator?

salimshah

I doubt that any one sells oem equivalent actuator. The door catch/latch is essentially two portions ..electronic lock and mechanical catch- intertwined [lexus sells them as one]. The labor to remove and install the assembly is not trivial.

If you check in the GS400 forum, some one found the motor that is an exact drop in.

IMHO, if you have advanced milage and old vehicle, piggy-back is the most cost effective and easiest. The only worry I have is if the work is not done right and the system jams up, the door may become stuck closed and rip up would be required to fix it.

Salim

motohide

Hello, I just tried to use an aftermarket push-rod actuator. However, the LS in my case as are most newer Lexus cars, have cable operated link to the door, so the only viable location was to attach it onto the striker/lock assembly.

But because the striker/lock assembly has to be removed to do this, its only a few more steps to replacing the motor in the original lock. Most often than not, the motor brush shoe spring has loosened over time and wear, and 90% of the time, simply bending the springs a bit to firm up the shoe contact does the trick for the next 5-6 years when it really does require a replacement motor, in my experience.

code58

motohide- have you actually taken them apart and gotten another 5-6 years out of them by tightening (bending) the springs? I did exactly that in my DIL's RX and it did essentially nothing because the brushes were simply worn out, period. I cut 3 of the 4 door actuators apart and it was pretty much the same with all of them. I'm used to doing this kind of thing and even though I bent the brush holders to hold the brushes tighter against the commutator, with brushes that are almost microscopic, it still was not successful. It would run, but like anything that is worn out, just no power.
And as for the cable operated linkage, most all of the "piggyback" ones that I have done are attached to the 90 degree fitting on the end of the cable. No problem!

thomas1

Hey Roger, I had to replace my piggyback last night, darn motor failed...Fortunately I still had a spare from the two I had ordered...Just ordered 4 more for the future..Wife was impressed that I fixed it so fast. Of course the engineering was aldready there, just replaced the piggyback solenoid...Solenoids on EBay are very abundant....

salimshah

Door not locking electronically is an end result of many possible reasons
I try to find a solution based on age, exposure and ease of fix ... this is different from diagnosing the problem. [When you diagnose the problem then you have to get down to worn brushes or not enough tension on the metal arms. Note each fail can be different].

After working with the actuator [which I thought I revived and it later failed after few weeks] I have come to the conclusion that it is not worth the time and effort (including tear up) to revive the old one and go for the piggy-back solution. The only tricky part is creating the attachment point on the thumb-flick-****.

Salim

motohide

My motor still had about 2mm of brush left on it so I sort of stuck it back in just to see how far it will last with springs tightened. Of course if it was any less, I would have simply replaced the motor. My car has only 55,000 miles so I was quite annoyed that this would already happen.

thomas1

Mileage doenst have much to do with it. It is a function of how many lock/unlocks are done. I have replaced mine twice.....

code58

Thomas,
I'm curious as to how long the original lasted and how long the "piggyback" aftermarket motor lasted. For what you pay for them it's amazing they'd last around the block but I think the quality of most of the motors in the aftermarket "universal" actuators are probably not far short of the Chinese motors in the insanely expensive OEM actuators. The quality LOOKS quite good on most of the inexpensive aftermarket actuators. I actually bought 6 for $15. plus shipping for 1 of the forum members. They work like a charm.

Thomas, if you're a curious soul like me, you will have already dissected that sucker to see what wore out. Likely the microscopic brushes.

thomas1

The original door lock assembly was replaced after 6 years, The OEM replacement last another 3 years, the piggy back last 2 years, and now I am on my second piggy back. I will take the piggy back apart today....