2012 Dodge Longhorn a/c Comes on Then Goes Off Comes on Again in Fee Minutes

• #44

I accept been following this effect (*Ram's Ac performance on 2019+ platforms) somewhat closely since the Gen5-1500 deliveries began final year. In fact, I delayed my buying decision as a direct effect of the Ram Ac outcome in the hopes FCA would come up forward with a real ready (I'm losing that promise, but not completely). On the positive side of that, the purchase determination delay has allowed my new truck involvement to expand upstack from the half tons to Hd's (Ram 2500 & Sierra AT4 HD). Over the months, I've test driven too many RAM vehicles , a small handful of Sierra 1500 AT4's & an even smaller scattering of AT4 Hd's (simply recently have they striking lots in my area).

Hoping to salvage folks some time with my effort at summarizing the numerous AC Operation/Problem threads (a couple of the threads are extremely long) from 5th GenRams Forum:

• Ram's Air-conditioning operation from the new fifth gen 1500 & 4.five 2500 is a thwarting to many owners (and some potential owners, self included).
• The most important fact per my readings & experience with the new Ram trucks: FCA changed the physical compages of the RAM AC systems from the prior gen models. New RAM Ac systems appear to be entirely dependent on an electronically-controlled blend door. Whereas, previous gen vehicles also had a heater cadre valve that helped ensure the truck'southward heater core was not bleeding too much estrus into the Air conditioning system vents/airflow.
• The behavior of the new gen Air-conditioning is not particularly consistent from i vehicle to the side by side. I directly observed this in back to dorsum test drives, multiple times. Owners' experience equally reported in 5thGenRam forums reads similarly to what I saw in person.
• I originally hoped the RAM Air-conditioning upshot was isolated to the 5th gen one-half-tons, but the Blend Door dependency also appears to be the prototype RAM/FCA used for the 2500'due south. I have non straight confirmed this on the 2500's, but anecdotally based on the air-conditioning functioning... it appears to be the instance.
• Some owners in the threads reported that the AC performance on their trucks changed over the course of time... from 1st date great to horrible... average to below average. Some have said their Ac started proficient and stayed good. Others reported the AC started bad and stayed bad.
• At present, it seems as though the new RAM AC systems are a box of chocolates. Unit variance of this degree scares me every bit a buyer. At least until their is a manufactory-backed solution reducing air conditioning perf variance down to a more reasonable level.
• Ram's blend door dependency for their HVAC has been a proven problem source (many times over) via diverse Ram owner-designed AC system hacks which use clamps & valves to isolate the heater core. These habitation brew fixes immediately improve Air conditioning system performance via meaning airflow temp reduction. Observed 8-12 degree vent airflow temp reductions appear to be a off-white expectation subsequently the AC hack of choice is performed.
• Ram Dealers seem to take been effectively trained by FCA or some other Wizard of OZ in accuse to say they have not "heard of any AC issues with the new trucks". It's almost comical how consistent they are with this bulletin, even when 5 trucks are rolling out of their service bay for AC issues.
• Fright non, the dealership service team volition most likely tell you ,the owner, that the Air conditioning is 'normal' later on their AC test protocol is complete.
• The 'new' govt mandated coolant type is a frequent scapegoat for the dealerships. The truck'south software version/settings are another common scapegoat for the AC issue. A software upgrade & coolant recharge failed to help about of the forum users experiencing the Air-conditioning upshot. It sounds like the software reflash primarily targets fan speed.
• Ensuring your coolant charge pressure level sounds like information technology is worthwhile though... given some users reported trucks delivered with inadequate charge pressures. But it doesn't remediate the issue for those with inadequate blend doors.
• The commuter side vent & the left eye vent are the most mutual offenders of uncomfortable AC vent temps. Users often reporting upwards of double-digit temp differences from those vents as compared to the passenger vents. It's amusing that the FCA engineers would allow the driver vent be the offenders. I mean, exist craftier and hide information technology in the rider or rear vents
• Setting aside all the dealership theatrics, isolating the heater core via hose clamps &/or valves has proven 100% constructive at markedly reducing the Ac vent temps.

Outlook related points:

• At present, it doesn't feel likely (to me) that Ram & FCA will admit that in that location is a 'trouble' or consequence an AC organization 'call back' whatsoever time before long
• There are handful of apologists that point out (rightfully and then) that many of these trucks' vent temps test out equally 'normal' when using the RAM AC test protocol.
• Unfortunately for Ram owners, the temperature performance thresholds in the current RAM Air-conditioning examination protocol are an absolute cake walk to hit. 'Passing' the RAM AC examination is so easy, my lawnmower could probably pass it likewise! Information technology reminds me of a time when I allow my engineers cull the perf thresholds for their own work. Judge what, their code somehow was Ever performant! haha
• The layup RAM Air-conditioning test appears to be designed to pass simply about every truck that doesn't have complete Ac organisation failure. This goal appears to have been accomplished & presently the performance test serves equally a stable crutch for dealerships & FCA to say everything is 'Normal'. Equally alleviation, the 'software wink' is then offered to the customer in hopes a placebo effect victory is achieved courtesy of leaf blower velocity coming through the vents with the new fan speed settings.
• The other crutch (which deserves a seat at the table) is overall cabin cooling adequacy. This would factor in air volume, not just specific vent temps from the commuter vents. If air volume of non-ideal temps is loftier enough... it tin can still cool the cabin the same as cooler vent temps flowing at lower airflow book. i.e. garden hose versus firehose filling a pool, small turbo versus large turbo, etc. On the betoken of total air volume, regardless of total cabin temp... blowing a higher book of less than comfy air on the truck's commuter is a bad customer sat approach.
• Admitting the beingness of an AC problem when the physical architecture of a system (blend door dependency) is the likely root is a very expensive admission. Particularly given how many units are already in customer hands. What's more than, the result is non rubber related (e.g. airbags, axle failure, brake failure, etc)... so the prioritization of ideal Air-conditioning operation is probably at the lesser of Ram'south pile . Unless information technology begins to affect sales in a material style, air-conditioning performance will not be at the tiptop of the upshot list.
• I love that the customer-adult Ac hacks well-documented on 5thGenRams are almost guaranteed to work. This is the one affair that is allowing me to keep Ram in the equation instead of only buying the HD AT4 (which will have it's own issues, then I wouldn't want to jump that shark likewise early).
• I am concerned about the AC hacks negatively impacting the warranty though, fifty-fifty though removing the hose clamp before service is non too hard. Although, going with a permanent valve would be my preference for a number of reasons... but that would assuredly crush the Ram warranty.
• The electric current alloy door's sourced by RAM for these new gen trucks are either faulty from the spring, have short lifespans of effectiveness, or are just non acceptable. Only fourth dimension will tease out that reply.
• Time volition besides tease out what (if whatever) other contributing factors may exist.

In the cease, I am thankful I didn't need to rush the buying decision thanks to other owned vehicles, simply I would love to just hit the fast-forward and be done with the decision. I've exam driven enough trucks this past year for a lifetime!

thanks all

Terminal edited: Aug 19, 2019

• #46

I simply dropped my truck off at the dealer this morn, 2 weeks to the day later on taking commitment. They were going to put a charge on it to "see if that helps", merely when they went to ring upward the service in their computer, all kind of alarms went off, being a 2019 with AC concerns. Then they are currently putting it through a bunch of diagnostics per the computer. I got a 1500 Classic Express as a loaner, and it's bravado way colder than my Limited 2500.

I am encouraged past the computer's direction of boosted diagnostics. The dealer told me this is the 3rd truck they've had come in for inadequate Air-conditioning. Hopefully FCA is taking this more seriously?

Last edited: Aug 22, 2019

• #55

If refrigerant type was the most cardinal change Ram/FCA made to the current gens' Ac's systems, refrigerant would be a proper FCA scapegoat for virtually of these Ac performance issues. The struggle is RAM made more fundamental changes to the Ac's compages than refrigerant type (i.eastward. no valve to isolate the heater cadre when Air conditioning is on). In practice, this can be demonstrated in minutes (on well-nigh of the trucks that won't blow cold). Isolate the coolant hoses from the heater core via a removable hose clench, the AC vent airflow temps will drop 10+ degrees moments later.... this of grade with the same refrigerant blazon & same refrigerant pressure. There are enough of trucks & cars out in that location using the current refrigerant type that do wonderfully.

Fast frontwards a few years into the future and Ram will add a heater core isolation valve dorsum or Ram volition take sourced an improved blend door that is up to the task. At present, it seems that some trucks take blend doors which are working as RAM hoped they would while others have troublesome. I've driven 10 or 11 of the electric current gen Ram's between mid-June - August during high-dew point & loftier-temp days. 4 of those had splendid Ac performance. A handful were just ok. 3 were horrendous though. Ane of the benefits of examination driving units off dealers' storage lots is that it normalizes for vehicle sit down time & UV gain. When I mentioned significant 'unit variance' in a prior post, this was the scenario behind the comment.

A factory fix would be awesome, but if it were simple (cost-wise for them)... they already would have washed it In house counsel & the CorpFi squad probably agree information technology is cheaper to not admit a problem until they know how to remediate it as cheaply as possible.

Last edited: Aug 26, 2019

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Source: https://hdrams.com/forum/index.php?threads%2Fa-c-issues-anyone-else.573%2Fpage-3