Hi,
I have a 2012 Ram 1500 Laramie Longhorn. I recently replaced the Condensor and Evaporator and did not get the great cooling I expected. The vent temperature is around 60 degrees. My thought is that my expansion valve isn't opening up enough to lower the temperature in the vents. Yesterday, I took a long trip and after 1/2 hour of highway driving, the vent temperature got down to 40 degrees. Now I am wondering if my compressor isn't working correctly at low speed. I just went outside and took a reading at 82 degrees outside. At idle, were looking at 30/170. At 1500 RPM, i get 20/175. My trucks interior is about 140 degrees in the afternoon, so it would take a long time to cool down. However, shouldn't my vent temperature be a lot colder than 60 degrees initially ? If not, should I look at the compressor next or the expansion valve ? Any ideas?

 

You ask if the vent temperature should be colder than "60 degrees initially." Do you mean you measure 60 degrees from the vent within several seconds of starting the truck when the cab temperature is 140 degrees? If so, I would say you're A/C is doing great. There's a lot of black plastic under that dash that is trying to circulate some really hot air.

As far as the part replacement, did you fully evacuate the system and leave the vacuum on it for around half an hour, then charge with the proper amount of R-134a per the system capacity?

-Rod

 

I pulled a vacuum to 25 psi for about 10 minutes before filling with the proper amount of freon. As for the vent temperature, is stays at 60 degrees for the whole 15 minute drive home. I open my windows right away to let the hot air out for a minute and then close them and set my AC for recirculate.

My wife 2007 Avalanche has ice cold air right from the get go. This makes me wonder what is going on. I practically have a brand new AC system (except for the Compressor and Expansion valve). Thank You in advance for your advise !

 

Interesting. When the A/C is on and the engine is running is the compressor clutch remaining engaged? With the manifold gauge set installed are the pressures rather solid while the compressor is engaged or do they bounce around?

-Rod

 

Compressor clutch is engaged. Gauges are steady and do not fluctuate. Cooling fan clutch is in great shape. The electronic cooling fan engages and it strong.

I have micro leak in the Condenser, so I changed it. When I change the Condenser, I added 4 oz of compressor oil. Could I have too much oil ?

 

I wouldn't expect that 4 oz of added oil could be enough to cause performance issues, but I honestly don't know. Everything you've described as far as what you did seems reasonable and correct.

-Rod

 

And here is the kicker... Expansion valves are cheap and can be replaced without pulling the dash apart. Except, the bottom allen bolt is stripped out. An easy out made it worse. I have to get a dremel tool and a metal saw blade to cut through the bolt and get the old expansion valve off. If I screw it up, I will have to pull the dash again and get it off the evaporator.

 

Is there any chance there's enough space under there for a standard length drill bit and a drill (maybe a right angle drill if you have one)? I've had good luck using left handed drill bits to remove stripped out screws and broken bolts, as long as they are not too rusted.

-Rod

 

Unfortunately, I've already manged the screw by drilling off center to the point where it cant get the drill bit to center on the screw.

Of course, Until I figure out if there is a problem with the Expansion Valve or the Compressor, I don't want to to do anything.