96 explorer NO HEAT... HELP

[bsquishy]

I have a 96 explorer eddie bauer v6 4L and for the last 3 Winters the heat has been going in and out. It works just fine as Winter approaches and then again as we get into early Spring, but right when its necessary, it starts blowing cold. No problems with A/C, just heat. I would really appreciate any help anybody can give me.

 

[jlsparky7]

Check the first link in my signature. Watch the thermostat and radiator flush videos.

 

[bsquishy]

I flushed the radiator and changed the thermostat. It has again begun working sporadically. Occasionally, I can switch it to MAX A/C for a second and I hear a thump (sounds like a door being slammed) and the A/C will blow warm, when i switch it to any of the heat settings (Vent, Def, Floor, etc...) it blows warm until I shut the car off, then it is a 50/50 whether it will be hot or cold when i start it again. I've read a lot about blend door problems, and I am not sure that is my problem. I've not read anything about hearing that thump sound.

Any suggestions?

 

[bsquishy]

Well, it appears that this http://www.explorerforum.com/forums/showthread.php?t=183742 has worked temporarily. It also appears that the actuator is shot. I'll be looking for one of those fairly cheap in my area.