My blower motor works in the following speeds on my 03 Wrangler: low, medium, and high. The only speed it does not work on is medium high. I am thinking I have another problem going on since the resistors are in series with one another. So could it be my resistor or something else? I replaced the resistor back in November. If I remember correctly low, and medium high would not work back at that time. I have read that blower motors get where they draw more current when they get older. I'm assuming worn brushes. Could this cause my new resistor to have gone bad? Could it be the speed switch? I also replaced it back in November as well.