I have a 2000 caravan, and recently the heat/AC has only worked on high. So, after research i changed the blower motor resistor. I noticed that the wiring harness was burnt when i took it off. Since there was nothing i could do at the time, i put the wiring harness back in. Once i turned the car on, the air was on high and wouldn't do anything but blow air on high. I went through all of the positions on the air switch and it just blew on high, even in the off position. My question is, is this because of the burnt harness or did i screw something up installing the resistor?

 

Could be the harness. Dealers sell a replacement pigtail for the harness meaning a new connector with wires attached you just splice in. May be other sources.