I have a 99 4 door Blazer and the front passenger side window stopped working. I went to roll it up and nothing. So I pulled off the door panel and pulled the wire plug from the motor and stuck my tester light in the plug and it lighted up when pushing the switch up and the same on the other wire down. So I figured it was the motor since I have voltage to that point. So I bought a new motor/regulator and installed it, and I get the same thing nothing. So I tried my test light again with the wires plugged in to the pig tail coming from the new motor and it worked going up but wouldnt go down until I put my tester on the opposite wire. And I tried the same thing on the old motor and it started to work!!
UGGH!! Is this a grounding problem or ???? Any ideas I would really appreciate them thanks.