temperature control will not work

I have an 99 Montana van.We cannot regulate the temperature by using the knob on the dash board. The temperature is was stuck on hot all last winter ,which is ok.When spring came we could not get it to go cool no matter what. finally one day my wife called me at work and said it went to cool and it was stayed on cool all summer , which is ok.Now it is getting colder and we need heat.We can turn the knob back and forth, back and forth and nothing happens,the air stays cold.I replaced this whole 3 knob module and it still does not work.If someone could just tell me where this flap is in the dash so I can work it manually I would greatly appreciate it. I tried to find it last spring and finally gave up.

The temperature control "flap" is driven by an electric motor that can be seen on the driver's side of the heater module. You will have to take off the driver side insulator panel to get to it.

There could be a loose connection, or maybe the motor has gone bad. I will try to find a picture and post it if I can.

Take Care,

Thanks a bunch. I found the motor ,removed it and turned the flap manually to heat. Now I can get a replacement.

Thanks a bunch. I found the motor ,removed it and turned the flap manually to heat. Now I can get a replacement.

Have the same problem. How did you get to this part? I can't see how to access it.