Wont stay tight wiper arm

to adjust wiper arms switch of the wipers to let them park. then under the cover on the arms there is a nut that holds the arm on to the splined tapered shaft. then loosen the nut then pull the arm loose of the taper and adjust it to the normally parked position retighten the nut

If you can move the wiper arm by hand, the nut attaching the wiper arm to the pivot is loose. There is usually a plastic cover over the nut. Lift the plastic cover up to expose the nut and retighten it

check to see if nut at the end of wiper arm is tight under plastic cap is tight the side near bottom of windshield if it is the wiper transmission is failed needs replaced

If only one wiper arm is out of sync it means that arm has come loose. To repair it take that arm off and activate the wiper to get it into park position. then re- mount the bad arm in the park position, making sure the nut is tight. Check the splines on the bad arm because they strip easily and sometimes have to be replaced if it does not tighten down

The wiper linkage connects both wipers together. Likely yours that isn't working needs to be tightened down on the stud it rests on. Pull arm off and make sure the stud turns properly back and forth, then retighten that arm. If the stud is stripped so bad the ridges are worn down where the arm clamps down, you'll have to figure some way to wedge the arm down tight on the stud.
Good luck.

You have an assembly of arms that hook to motor one for each side sounds like your left one has come loose or is at least slipping you will have to remove the crowl panel at the wipers to check .The wiper is held on by a nut. The nut is under a plastic cover at the pivot point of the wiper. Loosen the nut then align the wiper blade where it's supposed to be then tighten the nut.Its not adjusted right, remove the nut that holds your left wiper on, then pry it off the shaft, lift the wiper up all the way then just pull up straight off the shaft, then put it back on so it starts at the left lower edge of the windshield.---- First, start by checking the nut at the base of the wiper arm, if it is good and tight, then you have to remove the cowl and check the wiper linkage.If the linkage has come apart then you will have to replace the piece that has come loose.------
Getting, this possibilities checked will help.Thanks.Helpmech.

Check wiper arm where it fits to the shaft the nut may have come loose! if so reset the arm to its normal resting place & retighten!
if its ok then its more likely that it has come off its pivot under the csuttle panel
it may need a new pivot

i like to sea the personal earth

the arm for the other side has come off... it's usually held on with a C clip

Remove the wiper arms and then remove the cowl and you should be able to see the linkages then.