E 350 blower motor
Rock auto lists one for your van also...
Front heat/ac = YH1697 {#4C2Z19A706AA}
Rear heat/ac = YH1698 {#4C2Z19A706BA}
I know a lot of the newer vans have electronic climate controls though.. Maybe someone else will chime in..
This is a video a guy made about his 2007 E150 with the blower not blowing at all... At 12:14 he shines a light on the "bower motor resistor"... There is also a lot of other good information in the video showing fuses and controls..

It's the Resistor that controls the speeds, and with only high, it needs replacing.
I did my '05, and ended up getting the wire pigtail/connector also, the OEM was "welded" to the resistor, and no way it was coming off.
If you order the resistor, get the connector also.
Note, you'll need to remove the battery and the battery tray to get to the resistor.
Here is a video about changing the resistor and how to get the connector apart if it is stuck.. In the video the guy does not replace the connector but I would follow Wildman25's advice and use a new pigtail. I don't know the proper terms but once the metal connectors get hot the metal changes properties and will no longer make a good connection no matter how well you clean the terminals. The wire to the connector may also get hot an inch or so from the connector and change conductance properties. So if you change the connector, and you should, clip the wires back a couple of inches from the old connector till you see nice new looking copper wire.....







