Engine Size: 3.3L
Refrigerant Type: R134A
Ambient Temp: 95ÃÂ°
Country of Origin: United States
Would anyone know what the factory vent temps should be for a 2000 Dodge Caravan with rear A/C? Also,how do they check this,windows up or down,max A/C,what idle speed? I can't give pressures right know because I'm evacuating it now. I just need some more info once I start charging.
Thanks for any help, Rob
I have charged the system to the proper amount,and with the engine at a fast(1500rpm) idle, 100ÃÂ° ambient temp,set to max with the windows down, I am seeing 80ÃÂ° at the center dash vents. I drove the van about 4 miles at speeds of about 50mph and the vent temp was 60ÃÂ°. Is this within the proper temp range? I did A/C work on an '01 Durango and got the same temps,and someone on this forum(can't remember who) said that was OK by factory specs. This is about 40ÃÂ° cooler than outside temperature. It doesn't feel cold enough for me.
Also,the condensate drain is pouring out water,which tells me the evaporator is plenty cool. Could there be a blend door problem?
Thanks again, Rob
If I'm reading it correctly, at 1500 rpm, you get a mere 20 degree delta at the center vents, and a 40 degree delta at about 2500 RPM (approx engine rpm while driving at 50 mph on these vans IIRC). Even with extreme humidity, that seems a bit off. I have a 97 Town & Country w/ front & rear air, and it does MUCH better than that. I was getting an easy 40+ degree delta at 1500 RPM with an 80 ÃÂ°F ambient (low humidity though too). Even when the system is only half charged, I was getting 30 degree delta.
So to answer your question, the caravan is capable of far better vent temps than that. Do you have rear air as well?
Need low/high side pressures along with those ambient & vent temps at 1500 rpm to provide further help.
Edited: Tue August 05, 2008 at 10:14 AM by webbch
Pressures at 1500 rpm are about 40psi low side/310 psi high side. This is at the the ambient temp stated earlier. Also, this is after evacuating for 1/2 hour and recharging to factory amount. As I do some general repair work on the side, I have worked on this van last summer. It stopped cooling and I simply checked pressures and topped off the system. It has worked well until last week when the owner said that on a recent highway trip, smoke came out of the vents. She shut off the a/c for awhile,and turned it back on. She said it worked OK after that. I could not smell oil from the vents,so I considered the evaporator fine. I checked pressures,and they were similar to what I got after evac/recharge. With all the condensate water coming out,that's why I thought the blend door under the dash may be sending heated air through the evaporator causing high pressures. WHEW!!!
Anyway,that's about all I got. Let me know what you think.
97 T&C pressures
That's a link where I was having problems with my van. After finally recharging, it does seem to be cooling pretty well in the 100+ degree weather we're having. I'll have to try and find the pressures I recorded after charging it again (haven't been motivated enough to find the leak yet). The low side does appear to be a little high for what it's worth.
I'd think the "smoke" coming out of the vents was refrigerant given your description, which implies a sudden leak, and likely from the evaporator if it came out the vents, but it's odd that it held a vacuum (you did check that right?) if that were the case and that your high side pressures are that high. You may be able to get after it with a leak detector or UV glasses if the system has dye in it.
Edited: Tue August 05, 2008 at 8:40 PM by webbch
your pressures are off. your rear unit is operated off a thermo expansion valve which operates off of temperature and should get you 40 to 45 degrees. your front unit is also a txv but of a different type and is also called a "H" block and i believe that is where your problem lays. generally i try to get at 95 degrees ambient from 45 to 50 low side pressures at 1500 rpm and the blower motor fan at 3/4 (this simulates the 30 mph the vehicle was designed for) and between 180 to 240 psi on the high side. if the needle in the H block is stuck it will throw your pressures off. good luck
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