I apologize if the following is common knowledge or old information, but I thought it may help someone who is experiencing the same symptoms. The turn signal operation on my 2001 XC became increasingly erratic on both sides, sometimes not coming on, other times starting to flash then stopping, etc. Fiddling with the lever would usually to get them to start again but it was inconsistent. I searched previous posts to find quite a few related to SWM(Steering Wheel Module) problems, sometimes corrected by pulling a fuse to re-boot the module. I tried this with no success. It also seemed my symptoms were different in that only the directional signals were a problem, not the dimmer or trip computer control, or the emergency flasher. The fact that playing with the stalk influenced the action suggested that the stalk switch itself was the problem.
Until removing the top & bottom shrouds (after disconnecting the battery to be safe), I didn't know that the stalk switch was separate and rather easy to unplug without removing the air bag, steering wheel, etc. It is held in place by a couple of small screws and can be slid out of place by prying gently on a few plastic tabs that are then holding it.
Rather than get a new one ($100-$160), I decided to take a look inside for obvious problems. Taking one screw out that holds the circuit board revealed a small rectangular block with three contact prongs attached. This just pops out. As the stalk operation seemed visually OK in moving the plastic prong block, I decided not to pry any deeper into that part of the mechanism (although that looked to be easily done if required). I simply gently pried up on the three prongs to give them more tension when contacting the underside of the circuit board. After wiping off the contact surface of the board and applying a light coat of di-electric grease, I put everything back together and for now at least, the turn signals are working fine.
While my problem may not be the most common, I hope this helps someone who might otherwise get stuck with a switch replacement or worse yet, a SWM changeout.