Z31 window switch repair

If you have a window switch that will only work in one direction, IE. down works but up wont or vise versa. The issue is most likely the contacts on the window switch itself. you can confirm this by removing the window switch from the inner door handle and checking for continuity on the ground pole and the hot pole when you push the switch up or down. This Diagram shows you what pins should have continuity when the switch is depressed.

If you do not have continuity on one of the pole when the corresponding switch direction is hit then you most likely have a dirty contact. To remove the switch from its retaining bracket take a thin flat head screwdriver separate the switch housing from the retaining bracket as seen here.

Once you have removed the switch housing, separate the lower housing from the upper housing by using your flat head to pry the upper housing over the tooth on the lower housing.

Once they are apart you will have a plunger that goes up inside the switch actuator and a small spring that applies tention to the plunger. Make sure you do not loose these as they are easy let fly off into Narnia, and you will not be able to put the switch back together. On the switch itself you have two contacts that complete a circuit when you push up or down in order for the switch to function. These contacts are what we will need to clean.

As you can see in the photo the contacts are darkened and burnt. You can use light sand paper or the tip of you flat head to clean them until they are shiny.

Once you have cleaned the contacts you can now test for continuity. The poles should read as shown below.

Once you have confirmed that the two poles in the diagram have continuity when the switch is pressed in their corrosponding directions you can put the switch back together and test it in the car.