Drivers side wiper arm seems to be making poor contact with the windshield. Is there an adjustment?

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

Sometimes you need to bend the arm to put more pressure on the glass.

Your wiper arm is worn out. You need to buy a new one. Make sure you get a Volvo OEM replacement as the after market ones are junk. The springs wear out after a while resulting in loss of contact with the windshield.

indicates that the arm has turned on the shaft
loosen off that arm
place the wipers in the parked position , reposition the arm correctly and re tighten it

I have the same problem with a 2001 Legacy wagon. The problem is not as simple as the solutions above. Mine are adjusted to park as low as possible when off. Even so, the blade on the drivers side goes all the way off the windshield. The Subaru dealer wants to replace the whole wiper blade transmission for about $450. Looking online it seems to be interconnecting arms and pivot points that connect the motor to the wiper blade arms.

the wiper arm could need to be replaced
being loose could have have worn the hole in the wiper arm
or the splines on the wiper transmission maybe damaged
i would try a new wiper arm first
use BLUE LOCTITE on the threads and TORQUE the nut to (22 lb ft)
hope this helps

Yes you can adjust them yourself. First you need to check that the wiper arms are not bent. If not, remove the cap at the wiper arm base, under it u will find a nut, remove this nut. you should now be able to remove the wiper arm. (it is comon for caravan wiper arms to be corroded on. If the arm dosen't come off, you may need to heat up the wiper arm with a propane torch. be careful not to melt the plastic cowel under the arm. OR you can use a wiper puller or a battery puller. do not force it, you can break the arm, DO NOT PRY AGAINST THE COWEL OR WINDSHIELD.
Once both arms are off, turn your van on and turn the wipers on. watch the wiper posts, turn the wipers off and watch the wiper posts return and stop in the "parked" position. Turn the van off. Install the passanger wiper arm first, it is positioned closest to the bottom an inch or two above the black cowel. It should be parrallel to the cowel. next install the drivers side wiper arm. it is positioned about 4 inches above the passanger wiper. again running parrallel to the cowel and passanger wiper. tighten the lock nuts down (do not over tighten) wet down your windshield with glass cleaner or windshield washer fluid and test wipers. If they still hit you can lower the passanger one a little or raise the drivers one a little (careful you don't raise the drivers one too much or it will 'jump' off the windshield at the top of the wipe).
good luck, hope this helps.

Wiper Pivot Arm Removal and Installation

1. Lift the windshield wiper pivot arm to the full upright position.

1. Remove the windshield wiper pivot arm.
   1. Release the locking tab.
   1. Remove the windshield wiper pivot arm.

1. NOTE: During installation, it is necessary to pull the locking tab out to its full open (unlatched) position and hold while assembling the pivot arm onto the mounting arm and pivot shaft. Align the key on the pivot arm head with the keyway on the shafts. This will make sure the pivot arm is correctly aligned. If necessary, the key can be removed. To adjust wiper pivot arms, refer to Wiper Blade and Pivot Arm Adjustment in this section.
   To install, reverse the removal procedure.

take the caps off and rebolt the wiper arm back on if you need anything else go to collisionrepairadvice.com

the pivots under wiper arm are seizing up,take wiper arms off and cowl,lube pivots,or buynew