Van Fan Problem

My 2000 Grand Caravan has a problem with the blower fan. It does not always want to run. At its best, it does not run as strong as it used to and on longer drives (over 50 miles) it eventually slows down until it stops. There are other times that when it is running slowly, it will speed up as the vehicle accelerates. I have pulled it out and tested it and it seems to run fine in your hand although you can't tell whether it is at full speed. I have tested the connector and it reads a constant 12 volts no matter where the fan switch is set, even in the off position. Any thoughts?

I've been there, I had to replace the blower motor in my 98 Grand Caravan.