A/C - Heater fan switch
Either the switch or the resistor that's connected to the blower itself. There's a FSM Here that has diagrams and info on diagnosing Section 24-33:
http://www.rm-indy.com/wavefiles/2001ramsrvcmanual.zip
http://www.rm-indy.com/wavefiles/2001ramsrvcmanual.zip
My have the some think I find out I have a recall on my 96 dodge ram for a load on the wring to the fan switch. They are put a relay on the fan. You can go to dodge.com to find the recall. my was recall 875



