Power window blows fuse
Problem fixed as follows:
Purchase a package of five 30 amp ALC type fuses. Replace blown fuse #8 (30 amp). Perform the following test to determine if the problem is isolated to the driver-side front window.
-One at a time, (i.e. only push one window switch button at a time) operate each of the other three windows (passenger side and rear driver side), to determine if the problem is occuring only on the driver side window. If any of them blows the fuse, replace it with a spare and proceed to test the next window. Repeat for each of the three windows. The process described below may also resolve the issue on the other windows if any of them blew the fuse during this test.
-Now, operate the switch for the driver side window. It is expected to work for a brief period (<1sec), but may very quickly blow fuse #8. Replace fuse #8 with one of the new 30 amp ALC fuses.
Remove the door panel, by sliding the speaker forward and removing the three white clips on the bottom of the panel. Also, pry out the screw clip in the panel well, just to the rear of the switch assembly, and remove the plastic bracket that holds in the switch assembly. The panel can now be lifted off.
To access the window mechanism, remove the tape over the oval cutouts near the top. Also, temporarily pull back the white plastic cover over the bottom of the door. Disconnect the white electrical connector near the center of the door (has only a red and black wire for the regulator motor). Using a small battery (motorcycle battery) and jumper leads test the mechanism's operation by connecting the battery directly to the motor wires. Use insulated test clips on the male connector and be careful not to short the clips together. The window mechanism should operate, and by interchanging the jumper wires (reversing battery power polarity), you can make the window go both up and down. Only do this for brief periods of time, as the motor circuit is now uprotected, i.e. there is no fuse in this test circuit. If the movement of the glass seems strained over part of the travel path, apply WD-40 lubricant to the metal rotating pivot point. Also apply silicone spray to the rail guides for the sides of the glass (with the window in the up position) and to the metal horizontal tracks and plastic wheels near the top of the mechanism. Also, spray some silicone lubricant along the bottom of the window on the outside, just above the rubber stripping, and operate the window a couple of times. An up and down test should now result in very smooth and even window movement. Reconnect the motor power wire to its mating connector, replace the tape and white plastic cover, and then replace the door panel. The mechanism should work smoothly, and the fuse should not blow. Total cost: $3.03 for fuses and a little WD-40 and silicone spray which you probably keep on hand.
May 17, 2009 |
1994 Volvo 940