Driver Side Window

2001 Dodge Grand Caravan Sport 41000 miles. In the middle of last summer the driver’s side power window quit working. It refused to go down for a few days. Then all on its own it started working again. About a month later it did the same thing again. This time I brought it to an automotive electrician who started checking the switch with a test light. After about 2 or 3 minutes of testing with the probe and wiggling the switch the window started operating normally. I complimented him on a great job and asked what it was that was wrong. He said “I don’t know, I didn’t do anything, it just started working.” The window continued to work fine until now, one year later back in the middle of summer. It will not go down again. Any idea what might be causing this intermittent problem? Should I replace the door switch panel? What else could be causing the problem?