I have a 2002 Dodge Dakota Quad Cab, 4.7 V8, 204,000 miles, original owner.

I have good heat and cool A/C (used a lot hear in Austin, TX) but I no longer get a strong air flow with either heat, cold, on floor vents or dash vents. I pulled the blower motor and it spins from low to high really fast.

I observed and listened for various mode door operation including watching the door that lets in outside air (from under the cowl). What little air flows appears to come out the right vents per the HVAC selection.

I have been searching posts and based on that I am thinking I might have a clogged evaporator (one post said all air passes the evaporator). Another post mentions a dirty cabin filter, but I don't think there is one on this truck. I have the service manual and found no mention / location of such a filter.

The service manual says the mode door actuators can be diagnosed with a DRB III analyzer (I don't have one), but I don't think I have a mode door problem.

I am thinking I need to pull the HVAC unit out to inspect the evaporator. Hoping it is clogged, but does that happen often? I am the original owner and have not put this truck through any extreme conditions. Do leaves and junk make their way to the evaporator? Is there a way to clean the evaporator while it is in the truck?

Before I tackle this project I thought I would post up and see what suggestions you all might have. Any suggestions to further diagnose the problem... e.g. should I buy a DRB III tool and look for trouble codes with door actuators?

Your opinions are welcome....

 

Wish I could offer better thoughts, but all I can contribute is that on my '01 which I also bought new, I've always had an air flow issue on the drivers side. I also had air where it shouldn't have been almost from new. My own fault for not pursuing the issues with the selling dealer, but that was a PITA because of their distance from me.

Short version, I had problems with air flow several years ago and it turned out to be doors that weren't opening and closing properly. I had the problem resolved but now it seems to have returned to a degree. I notice that at times the A/C doesn't seem to be getting as cold as it should and even with the demo dial all the way on cold the air coming through the vents without the A/C running is somewhat warm. I did discover that if I spun the dial back and forth after one or two attempts the air did seem to be the correct ambient temperature, not slightly warmed up. I believe I saw something posted about a mixing valve or something along those lines that might be the problem. However in your case it seems more like an air flow problem all around. I think that becomes the dreaded dash removal and an attempt to locate replacement items that function as new ones are no longer available.

Good luck!

 

First your fan motor may be worn out old or even be sticking when I pulled my fan motor it turned very stiffly like glue was in the bearings. Have you ever replaced it? On your model Dakota fan replacement is easy just under the dash.

Second you could have dirt and or leaves sucked inside the HVAC box blocking air flow how to clean it out I don't know sorry. You could try using a leaf blower down an air vent to see what happens but take it easy.

 

I had similar issues and thought the blend stopped working, a major repair job. I replaced the blower motor resistor and it cured everything.