I have a 2002 grand caravan sport with front and rear heat/ac. When the a/c is running, there is a great deal of heat coming out only on the passenger side floor near the engine hump in the floor. There is a long rectangular opening in the bottom of the heater housing, that is where the heat is coming out. It's actually being forced out by the blower even though the air direction is set at dash vents only. The A/C is coming out of the dash vents as it should and is working just fine, about 50 degrees at the vent. The rear unit works fine as well. The front just can't keep up with the extraordinary amount of heat being blown out the bottom. Again, it's only coming out at the floor on the passenger side, no where else. Please don't suggest searching the blend door forum entrys, I've read *******ly everyone and could not find anything similar to mine. Can anyone help? I'd appreciate any help, thanks.

 

Welcome to DF
Okay, when you switch modes from floor to defost to vent. The floor vent on the passeger side has air coming out of it all the time, weather you switch to one of the other modes.

 

Yes, no matter what I set the control **** to, the heat continues out the passenger side bottom duct. Everything else changes correctly. If I have the A/C on and I change the control **** to floor, the cold air begins coming out of the floor vent on the drivers side but heat continues out the passenger side. If I set it to defrost, the cold air comes out at the windshield only and the heat keeps coming out at the passenger floor. If I turn the rear a/c on and turn down the front blower to the lowest speed, the car will cool down eventually, unless it's very hot outside, but anyone sitting on the pass. side never gets comfortable. I'll be happy to try anything else to better pinpoint the problem, just let me know and thanks for the reply. Nice avatar!

 

im thinking a blend door actuator problem even though you dont want to hear that

 

I agree as well. I worked on a dodge ram truck the had the same problem. What I found out was one of the blend/mode door was bent causing the same that you are having.

 

Thanks, guys. Is there a document of any kind showing the various positions of these multiple doors as the different modes are set? In other words, if I set it for a/c through the dash only, what position should all the doors be in, etc, etc. Without that, I'm not sure I could tell which door was not functioning correctly. If I understand correctly, the motors that position the doors function based on number of impulses sent to them. How does one get all these correctly positioned when reinstalling the unit? Maybe I'm getting too technical here, but I want to be sure I install it correctly the first time, I'd hate to have to do it twice. Lastly, what's the best way to test each of the motors to be sure they are working correctly. I do have a service manual in case some of these answers are available somewhere in it, I may be overlooking them. Thanks so much for the help, I'm sure this is repairable, just want to attack it the right way. Removing the dash, evacuating the a/c, etc., is no problem, it's the details when it comes to the box itself, that I'm a bit concerned about.

 

The cover probably fell off of the hepa filter opening. Does the opening look like this except missing the cover?

 

OMG, Tizzy1, you hit the nail right on the head. The filter is gone and so is the cover. Without it, it looks just like a factory vent opening. I'll get a cover and install a new filter. BUT.........why is the air coming out of that opening HOT? It truly feels like it is going through the heater core. If it is, then won't it be supplying hot air to the evaporator, greatly reducing the a/c's ability? I stuck a stick thermometer up in the opening with the car running and the a/c full on, covered the opening for about 3-4 minutes and the air temp read between 115 and 120 degrees with the van closed up and after running the a/c for about 10 minutes. The outside air temp today is 80 degrees. The temp at the dash a/c vent is only getting down to 60-62 and I'm positive the charge is correct, I'm running 37# on the low side and 210# on the high side. Do I still have a door problem somewhere. Is there a water shutoff on this thing that is not working in the a/c mode? I apologize to all for not knowing about the cover, but I think I still have a problem. Hopefully someone out there knows the answer. Thank you.

 

Okay, here's the latest. I've spent a lot of time studying the air box and how it functions. I think I've solved the mystery of the 120 degree air. All along, I've had my a/c gauges on the car with the hood opened. Apparently, the heat from the engine is being blown up against the underside of the hood, then deflecting right down into the cowl intake. Closing the hood dropped the air temp significantly. It appears that my whole problem was the missing filter and cover. I believe my issue is solved. Thanks, everyone for your help, this forum is great, keep up the good work.

 

I just want to thank you all first for posting this, and for those who answered as well. My feet have really been burning up while in the passenger seat of our van. As a quick fix, I covered the vent with a few layers of duck tape until we get the filter and cover ordered. I can now ride with my feet on the floor instead of on the dash, or tucked up underneath me.
I really appreciate being able to type in my exact question and finding the correct solution on the first try.