Driver side wiper arm does not move when wipers are on. Passenger side does. When wipers are off I can move the drivers side wiper up and down the window. When the wiper is raised off the window, it moves as if it is not attached. Is this a loose lock nut?

You mean wiper arm ? Probably broken wiper arm linkage bushing you can't see , under the cowling . Can you move the passenger wiper arm up an down without much effort ? An not the drivers side ? To see it or get at it you would need to pull wiper arms off an take cowling off to get at it . How To Install Replace Wiper Motor 2000 05 Chevy Monte Carlo Impala How To Fix Broken Wipers EricTheCarGuy

REMOVE AND BRING DOWN TO BOTTOM.

If drivers wiper arm will not move by motor operation and can be easily moved by hand ( with wiper on or off ) suspect disconnected/broken linkage. If wiper arm will not move by motor and takes effort ( With wiper on ) by hand... suspect seized wiper pivot

check the nut at the base of the wiper arm . There is a splined taper on the end of the wiper arm shaft and if this is loose then the arm shaft moves but it turns inside the base of the wiper arm.

Either the wiper arms are loose or stripped on the pivots or the wiper linkage is broken. Try tightening the arm to pivot bolt. If that doesn't work, remove the plastic cowling and examine the linkage. You can buy new linkage for it.

bent/broken wiper arms under the base of the windshield..remove the vent cover and service/replace broken parts.

sounds like the connecting rod between both wiper arms either broke or one of the keepers popped off under the connector for that arm..since the wiper system IS NOT designed to wisk snow off the window once accumulated, this can an does happen.. even seen motors get burned out doing this..cleaning the window first will save this issue and the equiptment. need to acess this arm<take off the vented peice below the windshield and everything should be visible there..repost findings

the wiper transmission which is also know as a linkage is stripped out

take the cap off the end of the wiper arm and tighten the nut

start the caravan turn wiper off with the switch remove the capon the wiper arm most of the time the nut holding the arm in place is loose tight it up and try it thanks pierre