The passenger window on my 71 El Camino keeps falling off the regulator. Is the channel that the regulator rollers ride in supposed to be welded to the bottom of the window assembly? What else might be causing this? I can't roll my window up or down without it falling off the regulator. Thanks.

Have you taken the door panel off and looked inside? I believe on this setup you have a channel that glues to the bottom of the glass, then the regulator has a roller that rides in this channel as it rolls it up and down. check that the channel hasn't come loose from the glass, and that the roller is not broken, allowing the glass to come off track. good luck, brad.