Hi,

My luck with this truck dosent seem to change anytime soon..

We had a really warm summer and my A/C dosent want to cool any more than to 70F..

I have ha a A/C tech draining and refilling the system. No leaks.
He also recorded the A/C when running. Bare in mind that its in Bar and celsius.

The cold side works between 6-18 Celsius (42-64F) According to the A/C tech the A/C unit works good?! But perhaps the A/C compressor should cycle more often?

Return line from the evarporator is cold, 36F so the A/C should be working properly? Also alot of water condensation under the truck.

But I still only get 70F air in the cabin.

I have read alot about blend doors etc and checked them.
- Inlet air mesh is not clogged, I have good airflow overall.
- Recirculation door is working properly
- Blend door is working and is intact.
- ALL modes works perfectly (Feet, front, defroster etc)
- I have had the fan out and managed to put my arm inside the tunnels
and the A/C evarporator feel cold, perhaps not freezing but I can only feelone side of it. Put a camera in there as well and the evarporator dosent look clogged..

If i choose hot air, it will come instantly and hot!

What could be my problem? Im out of ideas..

 

Did you have it in Recirculate when you did the test with both front windows down? What were the high side and low side pressures? Tech should have put 1.88lbs (stock fill) or 2.00lbs in the system.

 

You might try blocking one of the heater hoses off in the engine bay to see if it is possibly leaking the hot air in the hvac box to the cold air side. Does it get cold when you first start the truck and then warm up gradually? Do your high side readings stay consistent over say ten minutes of run time? Spooler has it right on with the charge weight. I usually bump the 1.88 up to 2 lbs even because the system performance and pressures respond well there in my area. By the way, can you tell us which part of the world you are trying to keep this truck cool in and which year model it is.

Reason I ask is ac problems rely heavily on the ambient conditions. E.g. Alaska is not as hot as arizona this time of year and Florida is a lot more humid.

 

Several things comes to mind. Did you have the system in recirc while measuring the temperature? What was the ambient temperature at the time of pressure measurements? Was there a fan blowing air across the condenser?

Here's a chart for ambient temp/pressure, both low and high side. These systems perform best when what the high end of the pressure range.

 

Thanks for the answers!

I bumped the "coolant" to 2lbs just to be sure but still the same.. Its a 2006 2500 Ram, which i use in the far side of the world where taxes are high and the weather usually cold.. Its the same, idle, 60mph and its consistant 70F air coming out no matter what.

But when the compressor activates i can actually feel a difference in the air coming out. 68F and then the compressor disengages and the air temp rises to 72 and this cycles...

I have tried different things, there is no difference with recirc or outside air. The door works, thou. Ambient temp was around 80F.

The charts seems to be pretty spot on for the number I seeing. Perhaps Im a bit high on the compressor inlet side. 40-50PSI instead if 25-35PSI. Otherwise the same as in the youtube link I posted.

My fan is blowing, but there is no difference at 0 or 60mph, still only getting 70F air from the panel..
Even tried to with cold water on the condesator to rule it out..

Next step could be to drill a hole just after the evarporator an measure the air right after.. ?

 

How long is the compressor engaged? From the video it appears to be cycling fairly quickly. Has the pressure switched been checked out?

 

A couple of seconds, you can se in the youtube link when the clutch engages, the temp drops on and as soon as the clutch disengages the temp rises again.

There is no pressure switch on an -06, only a thermistor measuring everything and communicating with the PCM.

There are pressure valves, but they are for safety and are only releasing the AC "coolant" when pressure gets to high. They have nothing to do with the cycling of the compressor..

 

How about the transducer? Also check the wiring around the AC compressor for chaffing. It's been a known issue.

 

Whats the transducer? Where will I find it? I will doublecheck wiring!

 

I know its an older post, any idea what fixed it?

I have a similar issue, 70 degrees out the vents.

 

Hello I Drive A 2005 dodge 3500 And Have The Exactly Same Problem Mentioned Here I Wondering If Any One Find The Problem?

 

Look up , Heater Treater. Net they make replacement doors, very informative videos, I replace some of my doors , these are made out of metal the factory doors and mechanism is plastic, Good luck

 

I havent ever been happy with my 2005 AC at all. I got a thermometer I leave stuck in my vent to watch things all the time It will get down to 48-50 out the vent after some driving and maybe 55-60 on real hot days of city driving. Usually stays 48-50 on the hiway no matter what temp outside. I did have a weird thing happen the other day while sitting in a drive thru. The air started warming up as we sat there. Acted like AC wasnt working at all. I turned it off and back on with no luck. My girlfriend pushed the compressor button and shut it off and then back on and it took off and has worked fine since. I even got a section of that foam tubing you put around water pipes to keep from freezing and with zip ties cut pieces to cover all the bare metal lines on the truck in hopes to get more cold into the dash. It made a small difference.


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