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Old 10-18-2008, 07:32 PM   #1
jetjock
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Default Master Window Switch Repairs

For those of you who haven't had the pleasure of working inside the driver's side Master Window Switch (MWS) I'm going to write about how to do that. Specifically about how to repair intermittent contact of the passenger window switch located in that assembly. While the passenger window switch in it's own door has been known to cause grief the MWS one can also act up.

The typical symptom is the passenger window refuses to go up or down when using the driver's side switch. Assuming the lock switch isn't enabled the cause is almost always contact oxidation. Before we get into opening the MWS to resolve that here's a trick you can try: with the car stopped and the key on simultaneously press both driver and passenger door switches in the direction the window needs to go. If the window operates stop and start it several times using the driver side switch while continuing to hold the passenger door switch. Do the same for the other direction then release the passenger switch and try using only the driver's side. If the window now operates normally you're done but this is likely to be only a temporary solution. In any case, at least you have a way to move the window until you get a chance to repair the MWS.

It's a relatively intricate device and care must be used when working on it to avoid damage or lost parts. Remove it by first removing the decorative plugs hiding the screws in the door handle. Note these plugs are not the same and must go back in the holes they came out of. Then remove the speaker grill and switch bezel. Both will pop off with slight prying. The four screws, two in the door handle and two in the speaker enclosure, can then be removed leaving the handle to hand by the harness connector which can then be unplugged by pulling it straight back while depressing the locking tang. The MWS can then be removed from the door handle by taking out the three screws located on the rear of the switch.

Place the switch onto a flat surface. Working on something while holding it in one's hands is a noob mistake that results in lost or damaged parts and injuries. Remove the passenger lock button cover by pulling it straight up but leave the passenger rocker in place. The next step, removing the main rocker to get at the screws underneath, requires care to avoid damage that will render your MWS junk. The pin in the rocker must be removed. Do that by carefully prying the left (outside) tab just enough to disengage the pin and raise it and the rocker upwards to where the pin can be grasped and pulled out far enough to release it from the opposite tab. Do not pry on both tabs or you'll likely break one. Do that and you're screwed.

Once the pin is disengaged fron both tabs lift the rocker straight up. There are two spring loaded plastic pins in the underside of the rocker. If they fall out the longer one goes on the left side with the rocker oriented as it sits on the MWS. Place the rocker and pins aside.

Under where the rocker was you'll find two machine screws. Remove these as well as the two sheet metal type screws on top of the switch. Once this is done the bottom portion of the switch can be separated from the top portion. Do so now, taking great care that the passenger lock switch remains inside the lower portion of the MWS. The lock switch is a separate assembly and if withdrawn from the bottom of the MWS a small torsion spring used in the latching mechanism will launch itself into oblivion. Prevent this by keeping the passenger lock switch inside the lower portion of the MWS when the top half is lifted off.

If the spring should escape and not disappear it can be put back in by turning the lock switch over and placing the spring on the small post with the short leg in the upper cutout and the long leg in the track at the bottom of the switch mechanism. Holding it in place reinsert the switch back into the bottom portion of the MWS being careful to guide in the contact points.

Now that you've finally got the thing apart remove the two metal contact strips for the the passenger window switch. They simply sit in the switch recess and may have already fallen out when you separated the switch halfs. Note they're silver plated, another testament to Toyota's engineering and attention to detail. The ends of these strips, as well as the fixed conatcts they mate with, will have to be dressed to remove burnt and oxidized contact material. While people like me (lmao, I'm not sure what that means) own real contact burnishing tools you can use a small wire brush or emery cloth. An old school trick is to use the striker portion of a matchbook. Use caution to remove only enough material to clean them up. You don't want to break through the silver plating on the movable strips.

Now is also a good time to clean the main window contact points. You'll find them at the end of the long copper bus bars on top of the assembly. Use the matchbook cover or emery by placing it between the contacts and slowly pulling it out. When finished degrease all contacts with an alcohol dampened swab and place the passenger switch strips back into the recess where they sit on top of the fixed contact points. Place a tiny amount of Vaseline or similar lubricant onto the two plastic pins that protrude from the bottom of the passenger rocker and also on the pins in the main rocker. If the factory grease is still abundant in the main rocker cavity use a bit of it for the passenger window pins.

Carefully mate the halfs together, reinstall the screws, and check passenger rocker and lock button for smooth operation. Prior to going further you should temporarily connect the switch to the car and test for passenger widow operation, assuming that's why you had it apart. Now would also be a good time to do the auto-up mod for the driver's window but since that can be found elsewhere I won't cover it here. Another mod is to changed the resistors to brighten the LEDS or even change LED color. I brightened them 50% because, well, I'm getting old and blind. Laugh all you want....it'll happen to you.

Anyway, it's time to reinstall the main rocker: Making sure the plastic spring loaded plungers are aligned center the steel pin in the rocker and gently push straight down onto the plastic tabs until the rocker snaps into place. Also snap the window lock button cover back on. The MWS should be complete at this point. Installation back into the car is the reverse of disassembly.
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