It was at least melted wires. Had to replace the resistor harness. Replaced the motor as well as I've already had to replace the resistor before.

 

I went thru the same thing if switch works on high only you need a new resistor they are cheap... do not go to the stealership...I got mine at Auto Zone. to remove the plug you have slide the little red tab over to the right to unlock the plug and just slide it off you can go online and watch any one of many videos on youtube very easy.... if it continues to happen as it did with me...you will need a new blower. I got mine for half the cost on Amazon....hope it helps

 

Guys again help is needed after you all told me how to fix my 99d 300k Blower problem fix an running fine now all my air goes up windshield and no where else so I looking for a diagram of the air flow hoses are supposed to go? I don't really know if or what i am looking for. any help would really be a god send cause it is getting hot around central Oregon.
TIA JohnNoregon

 

in 99 the blend doors are vacuum actuated, you have a vacuum leak, i believe there is a partial FSM for a 98 or 99 (vacuum layout should be the same) in the FAQ thread, follow the link to durango manuals