C4 Window Regulator Replacement

By Howard S

It started when the drivers window on our ’88 would not go down. We could hear the motor running, and when the window should have been going up, it would get forced into the weather stripping. It turned out that a weld between two arms on the regulator had sheared.

To replace the regulator:

1. Remove the door panel. On the ’88, there is a screw on the back edge and several across the bottom and up the front edge. You also need to remove the speaker cover. At the door handle, remove all the screws that hold the panels in place, including the 2 in the bottom of the handhold. The door lock button must be pried off the rod it snaps on to. The door panel needs to be lifted up, pulled away from the door and moved forward to get it free of the lock rod. Then remove the wire connectors.

2. Remove window glass. The glass is held in place by several bolts. There is also a stop post that must be removed to get the glass out of the door. This post has a nut on the back side and requires an hex key wrench on the inside.

3. Remove inner structural panel. There are several bolts that hold this panel on. Remove these bolts and work the panel free. I found that by dropping the panel down inside the door I could get the top out and work the panel free.

4. Remove window regulator. There are 2 10mm bolts going up thru the bottom of the door and 2 going down under the window weather strip. With these removed, the regulator can be worked free. It helps if it is in the window down position. In my case, I had to force the regulator arm down and tie it there.

Replace the regulator in the reverse order. The left and right regulators are not interchangeable.

The window glass will need to be adjusted for a proper fit. The holes in the glass are larger than the bolts and allow the window to be repositioned to line up with the weather stripping when the glass is up. If it hits into the weather stripping too hard, the bracket at the back of the glass can be adjusted to change the angle of the glass.