Edmunds Answers



  • jamst 08/15/10 7:01 am PST

    If you will look at vacuum diagram when you raise the hood you will be able to locate the port for climate control, crusie control and 4 x 4 if equipped. There is a line that elbows off with a check valve that runs into a tee and that line runs to the cruise control module, follow the line further it again goes in 2 directions, 1 line runs to the vacuum reservoir and the other to the climate control, if you pulled a vacuum to the climate control line you will not hold a vacuum for any amount of time, If you pulled a vacuum from the other line which go to vacuum reservoir you should sustain a vacuum because it is a reservoir. The only thing omitted from the diagram is the vacuum reservoir which in my case was test i needed to prove.It is located under the hood on the passenger side of the vehicle, Under the plastic shield. Help ?? see where the windsheild wiper assembly runs through gently raise that piece and bam there it is , now see the line check for it to hold vacuum.
    This turned out to be fine om my 1995 dodge ram 1500 2x4, so i went to auto parts store bought some plugs and capped off my cruise line,, Wow i never had so much power from the truck and vents work fine, I guess I have a bad cruise control module or possible bad line. I hope this is the trick that works for you..

  • johngah 08/21/10 3:49 pm PST

    I have a 1999 Ram 1500,5.2. I replaced the check valve and small piece of vacumme line and my crazy a/c vents stopped.

  • wisecat 05/31/12 3:07 pm PST

    I had the wild vents problem for a while, then the vents COMPLETELY stopped working. I could only turn on the defroster, or OFF. That is to say, no mattery which position I put the selector swtich in, it activated the defroster vents.

    I just fixed it, after many hours of going through vacuum lines. Frustrating, all my check valves were operational, and the only leak I found was a disintegrated elbow-connector in the vacuum line under the battery (connects to the cruise control canister, I believe). Fixing this did not fix the problem though.

    What was it? A LOOSE vacuum connector (multiple-line connector). The white connector behind the dash panel, that goes from the selector switch to the vacuum lines that pass through the firewall. (yes, those are vacuum lines, not electrical wires! It took me a while to realize that! ) I just unplugged the connector, and plugged it back in (took some real SQUEEZING to get it seated properly, all those gel-connectors inside of it that form a seal around the tiny little vacuum nipples inside the connector).

    Now I can select defroster, dash, or floor vent. I don't know if the 'wild vents' problem is fixed though, until I drive it (that is, the problem of it changing vents while driving uphill).

    I have a 2000 Dodge Ram 1500 Van. 5.2L engine V8.


Top Heating / Cooling Air Conditioner Experts View More

Rank Leader Points
1. karjunkie 1560
2. MrShift@Edmunds 1340
3. docj 375
4. tony78 375
5. texases 325
6. laltazan 320
7. 0patience 315