The front passenger window on my 2004 Trailblazer goes up very slowly. It goes down quickly. I have been reading the posts on broken window regulators, but not sure if that is the problem since it does operate. Can't see any places where it is sticking. Get the same slowness when using either the driver side control or the passenger control. Also read some posts about the control modules that may fail. How to trouble shoot those? I checked voltage at the terminals on the back of the passenger switch module by fol lowing wires from the motor and got low voltage (~10 v) when the window is going up, 11.5 when going down . Anyone have any ideas?