In my 96' 3500 the blower motor would intermittenly not work. Now It doesn't work at all, but then all of a sudden out of the blue it will work fine. It will not work 30 drives in a row then it will work. Then not at all for 20 tries then it will work one more time. I don't think its the resistor pack, or is it? It's not my daily drive but man when I do drive it I'M COLD!!! please help me. The only thing i could think of is the ignition switch???

 

does the blower motor make any noises like rattling or popping sounds? or does it function normal when it does work? its also possible that the heater control panel is going bad. When the resistor is bad the heater will usually work in the high setting

 

mines doing the same thing, motor is quiet.

 

I have the same problem on my 99. Works great when it works. I maybe driving down the road and the crazy thing may start to work out of the blue. One day it wasn't working so I turned the ignition off and restarted and it worked fine. I am thinking it's in the ignition switch, Is this hard to replace?Please help us Thanks