Another A/C question

[sevobuck]

Okay, so the dealership said that the whistling from my vent when the recirc door is on, is coming from my cowl. Apparently a couple of tabs on the cowl broke and the whole cowl needs to be replaced ($500). That is one issue...



The next is that the force of the air coming out of the vents is, (in my opinion) very low. The dealer says that is just the way it is but I find it hard the believe that the vents don't blow very hard. He says they had it completely apart and checked everything. Also the accumulator keeps freezing over anytime I drive for more than 30 miles with the A/C on...



I'm totally miffed by all of this and am about ready to sell the truck and start looking again.

 

[rscurtis]

When my recirc door went, it fell down and partially blocked the air intake for the fan. I had the same symptom- lots of noise but not much air. Remove the blower motor, a 5 minute job, and see what the recirc door is doing. The reason your suction lines are frosted is that there is not enough load on the evaporator- also known as insufficient air flow.

 

[sevobuck]

When my recirc door went, it fell down and partially blocked the air intake for the fan. I had the same symptom- lots of noise but not much air. Remove the blower motor, a 5 minute job, and see what the recirc door is doing. The reason your suction lines are frosted is that there is not enough load on the evaporator- also known as insufficient air flow.

Got it. I'll have them check it out. Thank you!

 

[B.G. Smith]

I believe the AC in your truck is supposed to have a thermister mounted on the face of the evaporator to prevent freeze up. could also be low on refrigerant. bg

 

[sevobuck]

I believe the AC in your truck is supposed to have a thermister mounted on the face of the evaporator to prevent freeze up. could also be low on refrigerant. bg

Dealer says the thermistor is located in the appropriate spot and is functioning properly as well. They have evacuated the system (again) and said there machine was malfunctioning. They said it was putting to little freon in the system. Took it home at it still freezes up! My truck has been at the dealership for the past 2 weeks (longer than I have had it!). Now I am back at the dealer and they are pulling the whole system and replacing all of the blend doors. Hopefully they figure out why it is still freezing up too. By the way the evaporator is brand new as well.

 

[B.G. Smith]

If the evaporator is icing over then the thermister(a solid state switch that opens or closes at a predetermined temperature) or something that it controls (stops the compressor) is bad sounds to me like. bg

 

[sevobuck]

If the evaporator is icing over then the thermister(a solid state switch that opens or closes at a predetermined temperature) or something that it controls (stops the compressor) is bad sounds to me like. bg

That's kind of what I thought too. I asked the tech and he said it was working within specs and that they are something that typically either work or doesnt work. I'm totally miffed. The dealer where I'm at has another Megacab that is an 07 and the A/C blows about like mine does but gets real cold real quick. Mine takes a good 10 minutes to get cool. I'm wondering if the dual climate zone has anything to do with it?

 

[sevobuck]

The evaporator is not freezing. The accumulator (a little frost) and most forward line (a lot of ice) coming out of the accumulator.

 

[sevobuck]

Well, I was sent home today without my truck... it took them a little longer to get the heatertreater doors in place. Don't get me wrong the heatertreater doors are a solid product but there is defintely room for improvement. I choose to have the whole plenum taken out to have the doors put in which is not the recommended way to put them in from heatertreater but I can't stand the thought of putting more holes in the plenum and then putting tape over the holes. This being said, there is a lot of "slop" when the factory actuator arm is placed into the heatertreater door. So much that if the hairpin that is provided is not bent a little, there is a possibility that the arm couold come out of the hole. Another thing that was not given much thought to was the flipper doors that divert air to the vents in the back (for the Mega Cab). Since there is no place to attach the actuator arm to the Mode 2 door (which also controls the flippers to the rear) you basically have to decide if you are going to A) fix the flipper doors in a permenant "half open" position or B) close them completely and have no flow to the rear. I chose "A" for the simple reason that if I wanted to divert more air to the defrost vent (because that is what the Mode 2 door does; defrost or floor) I could always reach back and close the vents in the back.
Other observations I noticed about the Dodge A/C system... there is a mesh screen that goes over the top of the vents on the A/C plenum that go to the center vents. This mesh is pretty tightly woven an something that I believe causes a great amount of obstruction to flow (and one reason why it sounds like the system is blowing hard and not much output; no, I did not have any broken doors). I have yet to prove that this screen is obstructive but I will find out tomorrow. I'm not 100% sure why the screen is there but if it is a filter then it is a poor one; maybe it keeps debris from falling down further into the plenum. I took a picture on my phone as an after-thought and as you can see I had already started to remove one side.
The second thing I noticed was the passenger side vent had approximately a 1/8 to 1/4 inch gap between the conduit and the vent which probably also contributes to such low flow out that vent. I taped it up nice and tight. Sorry for the rambling on and on but I hope that maybe this will hope other poor souls that own a Mega Cab Laramie.
#ad

#ad

 

[sevobuck]

After cutting out that mesh there is a notable difference in the air flow. The lines and the accumulator are still freezing up. Dealer says the recommended amount (1lb 14oz) is in the system. Anyone think having them put a couple extra ounces in will hurt? It blows cold air right now but what's going to happen once the accumulator freezes all the way over?