Hi Erik,
I've never done this but here are a few suggestions:
1. Take the cowls (the front part of an automobile body, supporting the windshield and dashboard) off and clean all the contacts, if that makes sense.
2. Another option is to get some Contact/Control Cleaner & Lubricant from Radio Shack or a hardware store. Spray the stuff in grooves and mechanics inside the steering column. Best to do this a few times and work it in real well. This will help keep everything from getting dry.
I've also heard, but don't quote me, that the switches are similar to Lancia's. So if you need parts look there. Others have rebuilt them and it isn't too difficult.