How important is the placement of the evaporator temp probe in the evaporator? Can the misplacement cause a vent temp problems? History is my 1998 Caravan 3.3 had the evaporator replaced earlier this month and I have always been able to get 45deg in rec. mode,Now the lowest it will go is 53deg and I have to use the fastest fan speed. If I use my normal second fan speed it will raise to 60deg. Have been back to the chrysler dealer 3 times now and they continue to tell me pressures are normal. What are they missing?
If it's too far in, vent temps won't be low enough. If it's too far out, the evaporator can ice up, eventually causing loss of vent airflow.
Not normal. Slower fan speed = less airflow across evaporator = more time for air cooldown = colder vent temps. Higher fan speed = more airflow across evaporator = less time for air cooldown = warmer vent temps.
Pressures have little to do with this -- sounds like something was not done correctly on the evaporator R&R. Mode doors not going all the way where they're supposed to, clutch cycling switch temp probe improperly installed, etc. They keep telling you "the pressures are normal" because they really don't want to tear the dash back apart to fix their screwup.
Um...why are you letting a dealer service department screw you, now that your vehicle's out of warranty?
Sure let Daniel give you false info again, The probe on the vehicle has to go all the way in untill it stops, thats the way it is designed The new evaporator that was installed has a hole set up for the probe to be inserted.
And Mr Stern should know by now that pressures have alot to do with proper effiency, To low and to high of pressures will cause lack of cool air.
You dont say what the ambient temperature is where you are from and that could have an effect on evap temp also, this chart is for your vehicle
Thanks for the reply guys. heres more info The vent temps I quote are both on 95deg days and 70deg nights the only difference is that during the day it takes much longer to cool because of all that glass in the van. The fan speed it still true fan speed high ,vent temp gets to 53deg turn it to second speed and the vent temp starts to go up after 15 minutes its at 60deg. I pinched off both heater hoses to the heater core no difference and when I push the rec. mode button I hear door close with increase in air movement noise. the question of the placement of the probe is that I asked for the parts back and on the old evap. I can see where it was supposed to be from the factory. It just so happens that on my van getting to the temp probe is pretty easy to see and it is not in the same position as the original. it is now much closer to the bottom of the evap. as evap. would sit in an installed position.
Glenn those pressures you list are much higher than the 2.2 Times the ambient temp. that I've heard about. what gives? does this Caravan need higher liquid l> > How important is the placement of the evaporator temp probe in the
Glenn is giving you his usual halfassed information...parts of it are almost correct, but he's looking in the wrong direction. If your mode doors are not operating properly, it's entirely possible to see acceptable pressures on the high and low side but still have unacceptable air temp at the vent. Likewise, if the temp probe is improperly installed (and yes, both "not far enough in" and "too far in" are possible), pressures will still remain largely normal. Grossly improper pressures will be evident only if there is a serious airflow blockage across the evaporator or condenser, or if there is a problem within the A/C plumbing (blockage, faulty condenser, faulty expansion valve, moisture in the system, noncondensibles in system, excess oil, under- or overcharge).
That's a good place to start, then. But really, I don't see where *you* need to be worrying about this overly much. Take the van back to the service department, and do not be satisfied with their irrelevant "the pressures are normal" answer. The vent temps are NOT normal -- they are not cold enough -- and since they WERE cold enough before you brought the van in, it's up to them to find and fix their screwup.
Perhaps you'll get "lucky" enough to visit the stealership where Glenn "works".
Daniel they say it's in spec. I say it not cold enough. They've have the car 3 times and it comes back the same. They have my money. I just think, as Glenn says something is wrong and now that he has provided me a temp/ pressure chart from Chrysler I can ask them to use it to recharge my van. Who knows how they're recharging it, if they even are. By weight or just 2.2 times ambient temp.Its just that the Chrysler chart says high side should be 290-380 psi @ 90deg much higher then I've read it should be 198/207 psi @90 .Why is Chrysler so much higher?
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Your system has a feature that will calibrate itself, If the doors were out of positon it will reset them to specs. If the door cannot be reset it will generate a fault code at the panel, I think Mr Stern Thinks we are working on a Dodge Shadow or an Acclaim. you can do this test yourself, im sure the dealer already did it, or hope they would have CALIBRATION/DIAGNOSTICS TEST ENTRY TO INITIATE TESTS: a.. Set Blower motor ON HIGH b.. Set Mode position to Panel c.. Open all A/C outlets d.. Set Temperature to Cold (Both slide pots if equipped) e.. Depress WASH and REAR WIPER button simultaneously for 5 Seconds (Until all LED's light) RESULTS: a.. All LED's will turn on for 5 Seconds b.. Calibration Test is running when REAR WIPER and INTERMITTENT are alternately flashing. Cooldown test is running if A/C and RECIRC are alternately flashing. c.. Acceptable results is REAR WIPER LED is the only LED flashing. Push Rear Wiper to exit. d.. After all tests have passed, Calibration Diagnostics and Cooldown can be run separately. COOLDOWN TEST ENTRY TO INITIATE TESTS: a.. Set Blower motor ON HIGH b.. Set Mode position to Panel c.. Open all A/C outlets d.. Set Temperature to Cold (Both slide pots if equipped) e.. Depress WASH and A/C simultaneously for 5 Seconds NOTE: Prior to start of test, If the evaporator is already cold, the system will fail test. To correct, operate system with A/C OFF and the blower motor ON high for three minutes prior to starting test.
RESULTS: a.. All LED's will turn on for 5 Seconds a.. Cooldown Test is running when A/C and RECIRC. are alternately flashing. If A/C and RECIRC. are flashing simultaneously, Cooldown has failed.
Glenn I ran the recalibrate procedure no errors returned Is that chart you posted correct that I should be 290-380 psi @ 90deg. Why so high? Do you think the tech would have used recharge by freon weight ,the pressure/temp chart or just 2.2 times ambient temp. refill procedure. I feel personally that it was 2.2 times way, that would explain why my vent temps are higher and it takes so long to get cool.not enough freon. do all chrysler products use that same chart or only Caravan?
Don't just accept "it's in spec". Escalate the matter. The A/C was performing better before you brought it in -- you need to emphasize that to them.
Typical dealer "service".
The chart Glenn provided you is contained within service literature the dealer has. If they're choosing not to use it -- which is quite possible
-- you stand little hope of changing their mind by telling them to do so.
Perhaps you are reading information applicable to older R12 systems, which run at lower pressures, or you're simply reading inaccurate information. High side pressure of 198/207 at 90F would be low.
That chart is from the 98 manual. If your system is overcharged or under charged you will get this problem, If you arent happy with it, tell them to recover it and weight it, then recharge again. I would bet it will get colder
Tim I know how the a/c was proforming because I have owned it since new and I keep a thermometer in the center vent 45deg since new. I have learned reading these forums that one of the first signs of a low charge is a loud hissing noise from where evaporator is, it's expansion valve noise. and I did have that symptom a few day's just prior to it having trouble getting to 60deg thats when I known I had problems. still I need to know if 290-380 psi @90 is proper high side psi. The chart that Glenn posted says yes but everyone else says its too high.
Its not ego, just trying to put the facts out because you Tim sound exactly like the people at the dealership. Lots of talk no action and no help on trying to solve my problem so just stop responding to this thread.
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