Just wanted to make a post to help anyone else out that is having trouble with there Jeep. My wife's Jeep Grand Cherokee Laredo started with intermittent cooling/heating issues about a year ago. The issue was that although the fan blew at all speeds, the A/C never worked all that well in the Louisiana summers. After some research I figured it was a blend door failure and talked it over with my wife about the insane repair bill vs the online kits. She did not want me to do any mods to the car at the time. During the winter the heater would seem to work intermittently as well and would blow hot some mornings and not others. Her model has the manual temperature control. I finally convinced her to allow me to check the thing out one day.

I found that the blend door rod was intact and that the doors seemed to be functioning normally. The blend door actuator on the other hand would only partially respond at times and would also reverse its direction at random. This would leave the blend doors mixing warm and cold air at random. I bought a replacement actuator and thought this would fix the issue. It did not.

I could never find a consensus on whether the climate system was vacuum or electically controlled. After check ing all the vacuum tubes and fuses, everything seemed fine. I found that by pressing firmly on the climate control assy on the dash and found that it would work much better, but misbehave if left alone. I ordered a replacement and now everything is working just fine.

For further reference; the seat heater controls, 12v power outlets, fan speed control and temperature blend dial all seem to be electronic controlled. The dial to shunt air to specific vents has vacuum tubes running to it alone, and are likely a mix vacuum/electronic control. I hope this post helps people searching for a cheap fix for there Jeep Grand Cherokee.