Good Evening all

Name is Jim, i just replaced the blower motor in my 1999 Dodge Ram Van and i noticed when i replaced the resistor that there was a lot of debris(leaves,twigs even straws) and the airflow is low, i have gone through close to 5 resistors over the winter/summer so i believe the air intake area is clogged, question is how do i clean this area. I am currently on vacation and have some time, so any/all help TIA.


Jim Henry
jimcomm4@gmail.com

 

Most people find they have to disconnect the AC lines above the climate control box in order to open it enough to be able fully clean all the leaves/dirt out.

I simply removed all the self tapping screws that hold down the top of the evaporator/heater box. Then I removed the heater resistor completely. I pried the top of the box open about and inch and wedged it, holding it open using a block of wood. I also gently moved the fin sensor and its wiring off the side a little bit, being very careful. I was then able to use a small 1" vacuum hose attached to my cheap household DirtDevil vacuum cleaner attachment hose and vac out most of the debris.

Vacuum the box out though the resistor block hole or through the top gap while gently brushing the debis loose with whatever small brush you can get in there and just do the best you can with the space available. I used a custom turbine wheel brush that can be found at auto parts stores, but a small dish scrubber brush, long toothbrush or anything similar with nylon bristles will work. I couldnt get the front of the evaporator 100% clean but I was able to remove 70 - 80% of the leaves and junk that were clogging up my evaporator.

It is certainly not a perfect solution and you won't get all the crap out. But it improved the airflow and worked well enough for me until I finally got fed up and replaced the evaporator core a year later.

 

Thanks for the response, i'll try this, i need better air flow for the New England winter

 

No problem. As I said it worked for me and I had a huge pile of dirt/leaves blocking my evaporator coil and getting almost no air was getting past all that to my vents.

Be especially careful with the wiring and sensors because obviously hard old brittle wiring and connectors break easily. But you can pry the top of that plastic box open pretty firmly, I had mine pried open so wide and with such force to the point I thought it might crack. But I needed at least 1 - 2" clearance to do the job so it had to be done. In the end it was fine and no damage occurred to the box whatsoever.

I figured it was worth the hassle to get that evap clean because even if the lid cracked or broke I could always just silicone it back together. Good luck.

A second place to clean/inspect is inside the squirrel cage (blower fan). Remove the passenger front fender and set the climate control settings to fresh air (to open the fresh air blend door). At this point you can see right inside the squirrel cage and part of the intake venting. You may be in for an unpleasant shock: my squirrel cage fan had a very large plastic grocery bag trapped inside it and that obstruction ended up being a big part of of my air flow issue! I've heard of squirrels and other rodents making nests in there too

Good luck!