silvel2edge

They mentioned a sensor... but I can't remember which sensor they were talking about. I just hope they can fix it on Monday. Cause I asked what the next steps are if they can't figure it out and they said they have some other avenues they can go down like see if any other dealers have had the issue or they may have to ship it to Chrysler's engineers to review and I'd have to get a loaner.

I really hope it doesn't go that far... ugh

tkob1060

umm I THINK you would be the first one to have your Jeep "shipped" to their engineers......that sounds really CRAZY, man dealers will say anything but who knows

Good Luck

JeepaRoo

oh i have been through this one before so much with A/C...

our JK's use a TxV as well as an evaporator temperature sensor for cycling the compressor... most likely you will notice constant cold air at idle however it will cycle when the revs are up a bit more...

Jeep locates the temperature sensor closer to the evaporator inlet than the outlet which will allow the system to cycle a bit earlier than you might want...

it also causes the system to cycle a bit more on cooler days.. which is a real pain because on our jeeps it can get hot inside on a 70 degree day (black top, black jeep).. or you wantto run with the windows closed for comfort but cant get cool..

my 2009 works better than my 08.. but from what I understand this is just a standard 10k thermistor sensor in the evaporator...

i am in the process of reverse engineering the system as jeep says and will say at the dealer your system is operating normal..... if it truly is just a thermistor you likely can drop a 150-200k ohm resisitor across the thermistor to ballast the resistance value and hold the compressor on a bit longer..

good luck at the dealer because i have been there many times with my 08 only to be told its normal... my 09 is better but still the vent temps go from say 45 up to 58 then back to 45 and bac up to 58.... my 08 was about 50-60 temp range on cycle...

there is no user or star-scan programmable parameter to change the setting on this sensor either.. I have been that route too....

kind of sad when my 500 Horsepower 1986 Monte carlo with a sanden compressor blows 36 degree air and my $30,000 jeep wont come close...

I was also through this with my 05 colorado truck and the thermistor trick fixed that A/C so im hoping to do the same with the Jeepster..
-Christopher

silvel2edge

Hmm... that's very interesting. The dealer and their AC guy felt it as well and acted like they haven't seen it on their other Jeeps though? I mean if what you are saying is true, wouldn't this effect all stock Jeeps? Also my buddy bought his rubicon same day as me, which was 2 weekends ago although his is a 2 door and he doesn't notice it. I'll have to get in his and see if I notice it.

jeep08ham

The AC has an expansion valve. Listed below is from the manual.




The A/C expansion valve controls the amount of refrigerant entering the A/C evaporator. The A/C expansion valve is of a thermostatic expansion valve (TXV) design and consists of an aluminum H-valve type body (1) with an inlet port (2), outlet port (3) and an integral thermal sensor (4).

The A/C expansion valve is located between the A/C refrigerant lines and the A/C evaporator in the engine compartment.


Hope this info. helps you.

JeepaRoo

what drives me buggy about this whole system is that with a true txV system you should never need to cycle out the compressor.. you vary the flow of refrigerant based on the temperature of the suction line.. but chrysler uses Both... a well built txV system will push the evaporator temperature right down to the limit just at or above freezing which results in air into the mid to upper 30's depending on blower speed...
-Christopher

JeepaRoo

ok guys... preliminary test results!!

I am running an 18K resistor in parallel with the evap temperature sensor and im getting consistently air into the low 40's.. ill drive it a bit and see how it goes... make sure i dont get any icing across the evaporator or such

im thinking a 20k resistor might work better..

the connector for the sensor is easy to get to.. once I know if this works consistently ill do some kind of write-up on it..
-Christopher

robin

I haven't noticed any of this in my jeep, the AC works fine

JeepaRoo

its all relative a lot of times... 50-55 degree air feels fine to some people.. others like it a lot colder... the OP's A/C may be out of spec.. but I know that the system in general is designed around that air temp of 50-55 from the vents... im used to the 36 degree air i get from my Monte.... and the 41-45 degrees that a buddy's silverado shoots out...
-Christopher

PA RUBICON

with summer coming, i ran mine to the dealer this morning. no issues. just low on freon. charged and good to go. warranty.

firestone wanted to charge my gf $179 for a check on the ac this past weekend!!! place up the street does it for $40 plus freon.