poor a/c performance

[ichoplin]

Well, I did what I said I wouldn't do, I pulled the dash again. It sure comes out faster the second time around.
Anyway, There is nothing anywhere blocking the ductwork on this truck. I've blown air through every passage I can find and all I get is dust and a lot of air.
Could my blower motor just be bad? I turned it on while it is out and it's really loud even out of the hvac system. O'Really;s has one for about $100. Anyone used one of these yet? I have to say, the motor, to me, doesn't seem to move that much air outside of the duct. I know it probably creates a venturi effect when installed, but I expected much more. That 2010 dually I drove today sure got cold in a hurry!
Ian

 

[ichoplin]

Just a thought, if my heater core was clogged up with dust, etc. . , would that cause my symptoms of poor air flow out of the vents? Or is it out of the equation at this point? the air from the vents was plenty hot this past winter.
Thanks,
Ian

 

[RankRam]

Could my blower motor just be bad? I turned it on while it is out and it's really loud even out of the hvac system. O'Really;s has one for about $100. Ian

I don't have any advice for you, I do have a link that might help ya though.





2006 Dodge Ram 3500 Truck Heat Fan Blower Motor - AM Autoparts

 

[sag2]

If you have a Mega Cab there is a screen that blocks some of the flow to the front so the rear passengers get enough air flow. There is a parts tech tip that says to cut the screen out. We did my neighbors and it did help some. I have heard some techs say they can clog with dog hair. The HVAC box does not have to come out to get to it. You will see it when you roll the dash back.

 

[ichoplin]

According to this drawing, all the air that moves through the hvac, must first go through the evaporator, right? What if mine was so clogged that the air was being restricted? Is this a possibility?

When I stick my hand up through the blower motor hole and go toward the driver side I can feel what I presume to be the evaporator. Is that what I'm feeling? The heater core is a little more toward the driver side correct?

If the evaporator is very clogged, anyone have any tips for cleaning it without removal(if possible)?

Thanks,

Ian

 

[ichoplin]

I think I've figured out my poor airflow problem, my evaporator is clogged pretty badly. I removed a few of the gold screws that hold the hvac box together and was able to open it up enough to see the fins. They are FULL of mud. I guess it makes sense that the accumulated dust would become mud there. Anyway, now to clean it off. My local tire shop gave me some "evaporator cleaner. " It's soaking right now, so we'll see how much of that crud will dissolve. Would oven cleaner damage the core if this other stuff doesn't work?
Ian

 

[ichoplin]

Success! I finally have air from my vents. It seems every issue I've had with this truck is from the PO and all the dirt/dust/mud. I've had overheating issues b/c of a clogged radiator and now I've had a/c issues b/c of a clogged evaporator.
The stuff I got from the mechanic worked some, but I had to resort to Simple Green and compressed air to get the majority of the gunk out.
Just goes to show, it's not always a broken door.
Ian

 

[DZink24]

i've posted on this numerous times in the past, i have some pictures of my evaporator, which is not dirty at all... what is the story with this thing? is the evaporator a fixed part, or should it slide back and forth?? my recirc door flaps back and forth as it should, and the a/c under the hood and associated plumbing actually gets coated in ice, so coldness isn't an issue. and when i reached up and felt the evaporator, it felt like a block of ice. since i can't post pics twice, i'll put the link up

https://www.turbodieselregister.com...-ac-flow-resolved-well-kinda.html#post2160991

 

[BGlidewell]

i've posted on this numerous times in the past, i have some pictures of my evaporator, which is not dirty at all... what is the story with this thing? is the evaporator a fixed part, or should it slide back and forth?? my recirc door flaps back and forth as it should, and the a/c under the hood and associated plumbing actually gets coated in ice, so coldness isn't an issue. and when i reached up and felt the evaporator, it felt like a block of ice. since i can't post pics twice, i'll put the link up
https://www.turbodieselregister.com...-ac-flow-resolved-well-kinda.html#post2160991

what you describe is exactly what happens when the system is low on refrigerant. go to walmart and get the can with the gauge to refill/check the low side. ~20 bucks

 

[DZink24]

huh. i'll be. thanks for the info. i'll give it a try. any idea why low refrigerant actually makes it too cold?

 

[Crunch]

what you describe is exactly what happens when the system is low on refrigerant. go to walmart and get the can with the gauge to refill/check the low side. ~20 bucks

Just make sure you buy the gauge/dispenser as a singular item and *not* the kit that comes with the R134a. The R134a that comes in the kit has the sealant in it, which could cause you many expensive headaches down the road. But the R134a separately, making sure you get the good stuff without additives. I've also seen the "ultra synthetic" around, and while I've never heard of organic R134a my preference is to go with the stuff that has the fewest words on either side of "R134a".

 

[BGlidewell]

huh. i'll be. thanks for the info. i'll give it a try. any idea why low refrigerant actually makes it too cold?

This happens on home ac systems too. I can't explain why but that's what happens. Every year my smaller ac unit freezes up at the coils and they put a few pounds in.



On the truck you will notice the vent temp will rise when the truck is at a stop around 25 psi or so. IIRC the truck needs 35-40 psi on the low side. Yours will probably be lower than 20. If it's not. Cry uncle.

 

[BGlidewell]

Just make sure you buy the gauge/dispenser as a singular item and *not* the kit that comes with the R134a. The R134a that comes in the kit has the sealant in it, which could cause you many expensive headaches down the road. But the R134a separately, making sure you get the good stuff without additives. I've also seen the "ultra synthetic" around, and while I've never heard of organic R134a my preference is to go with the stuff that has the fewest words on either side of "R134a".

I would not pose the warning that way. Here in Texas the walmart sells the all in one withbthe sealant but they sell the refrigerant an dye singly in separate cans with an additional gauge kit. I've used the sealant before with no problems. YMMV.

 

[Crunch]

I would not pose the warning that way. Here in Texas the walmart sells the all in one withbthe sealant but they sell the refrigerant an dye singly in separate cans with an additional gauge kit. I've used the sealant before with no problems. YMMV.

Sorry. Typo on my part. I meant to say "Buy the R134a separately, making sure you get the good stuff... ". Personally, I'm also wary of dyes, since Dodge no longer ships these trucks new with dye.

 

[rscurtis]

I would not pose the warning that way. Here in Texas the walmart sells the all in one withbthe sealant but they sell the refrigerant an dye singly in separate cans with an additional gauge kit. I've used the sealant before with no problems. YMMV.

The sealant is no problem until you open the system up for a future repair. When it makes contact with air, it becomes hard, rendering many system parts unuseable again. It does the same thing to any recovery equipment. There are now kits on the market to test for the presence of sealers so that techs can send a contaminated vehicle on its way without ruining their equipment.

 

[BGlidewell]

The sealant is no problem until you open the system up for a future repair. When it makes contact with air, it becomes hard, rendering many system parts unuseable again. It does the same thing to any recovery equipment. There are now kits on the market to test for the presence of sealers so that techs can send a contaminated vehicle on its way without ruining their equipment.

I've heard this before. I have not encountered a problem with the sealant becoming hard.

 

[DZink24]

there is a guy about 2 miles from me that appears to be in the HVAC trades by the looks of his van. he has had a sign outside his house the past few years offering $60 a/c recharges. instead of going to wal mart and spending 20 bucks or so, and risking messing up the a/c system, i am probably just going to call him, see what he thinks, and see if he can check my pressures and top my system off. it would be a small price to pay instead of walking into a dealer with a very expensive problem.

 

[BGlidewell]

that sounds like a good plan to me.