Expert: Ben Menard - 3/9/2010

Question
The passenger window goes down, but slows midway.  The driver side window will only go down a bit and will not go any farther down.  Is this a regulator problem?

Answer
Hi Echo,

It is very difficult to say what your problems are with so little information available.  Let me describe the most common problems.  Then you can compare your situation and see what seems most logical.

MOTOR PROBLEM:  
If the window will go down, but has trouble going back up, it is usually a sign that the motor is getting weak and will need to be replaced.  I recommend that you spray the channels at the front and back edges of the glass with spray silicone before you condemn the motors.  You can find spray silicone at your neighborhood Home Depot or Lowe's.  Use the least expensive silicone you can find.  It works just as well as the pricey stuff.  Just don't use anything but spray silicone.

REGULATOR PROBLEM:
I believe this window regulator uses a single arm to lift the window up and down.  The end of the arm utilizes a guide that slides back and forth in a "lift channel" under the glass. Typically, the glass also has some sort of guide on the front and back edges of the glass to keep it tracking in the window "run channels".  When any of these components is not working properly the glass usually falls out of the tracks and tilts forward.

Feel free to send me a follow up now that you have a little more information to work with.

Ben ... the power window guy.