Auto Air Conditioning & Heater Repair: 2001 Dodge Ram A/C goes full Hot-Cold, pain in the butt, mechanical knowledge


Question
A/C goes full hot to full cold intermittently.  Using the temp control knob has no affect- not variable. I hear a lound thump sound in the dash and all I get is HOT air, but generally within 10 seconds it goes back to cold.  I've been told the blend door motor is probably bad.  Where can I get directions on how to repalce this item, can a layman does this?

Answer
Larry,
If you send me an email address in a follow-up to this question I will send you a file with the directions I get from my online repair service. Mark the follow-up as private however so the world doesn't get your address. If you don't want to do this, Alldatadiy.com has one-time use rates fortheir online repair manuals, I believe. They are usually fairly decent on the information they give.
Can a layman do this? With some time, and a few tools, a little bit of mechanical knowledge... yes. But it can turn into a pain in the butt with alot of crooked neck positions involved. I would recommend taking it to a shop just to save the hassle. They will also be able to narrow it down to exactly what the fault is.
And yes, it sounds as though your blend door actuator has weakened or the vaccuum line leading to it has developed a leak. But this could also be he vaccuum harness connector (a connector that routes the vaccuum through different valves depending upon where you select from the dash control) or the selector switch in the control head not sending the appropriate signal to the vaccuum connector telling it which valve to vent or vaccuum. (This is one of the reasons I would take it to a shop... narrow the fault down)

Thank you for the question, I hope I was of some assistance. If I can do anything further during this process, or in the future, please do not hesitate to ask. If you found this response to be of some assistance, please remember to rate this answer. Thanks again and good luck in everything.