Hello
I had the same problem with my 91 town car. The switch was dirty and not making contact. I used some electric contact cleaner in a spray can to clean it out. I took the switch out of the panel, and pulled the plastic chrome switch top off. I hosed it several times and worked the switch back and forth. Finally it was working just fine. It took a while to clean it up but it was worth it,I didn't want to have to buy a new switch. Good luck
Mike