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A/C blowing hot air while idle

96K views 31 replies 12 participants last post by  dmcelhannon 
#1 ·
Been trying to search for a fix, but it seems like other posts were having problems with the A/C blowing constant hot air while idling and driving.

My A/C blows cold, when going down the road, but blows warm when idling at a stop light or just in park. Came across a post that mentioned a compressor fan, but I didn't see any other fans besides the cooling fan for the radiator.

I did check the relay labeled A/C and it seemed fine based on the manual.
  • continuity between terminals 87A and 30 - good
  • no continuity between terminals 87 and 30 - good
  • resistance between terminals 85 and 86 should be 75 ± 5 ohms - measured about 90 ohms, so not sure if that's an indication of a bad relay though

On a side note, (couple of months ago) my heater started experiencing a common problem, where the back vents blow cold air instead of hot. Not sure, if it's related to the same issue.

2002 Durango SLT 5.9L 4x4

Appreciate any help on this. Thanks.
 
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#2 ·
when was the last time you charged the ac system?
i had that happen on another car, and i bought a can of ac charger...and it worked.
also check for leaks.
 
#3 ·
I'm agreeing with what D72 said for the low charge, as far as the back, it's probably the mode door is stuck. It could also be the electric coolant pump has failed, but IDK if that would completely prevent free flowing coolant from reaching the heater core.
 
#4 ·
My Durango had the same problems. Check the relay for e-fan, if that's okay your problem is your e-fan. I've replaced mine 3 times in 8 years, they run about $110.00. These fans do have two speeds. Which I didn't believe, but I just did a replacement last week, my AC back at 45 degrees full time here in Hawaii. Good luck.
 
#5 ·
Following up...

Didn't really need a charge, but went ahead and topped it off. It's still blowing warm air while idling and cold when driving.

Noticed the compressor is making a clicking type sound, but that could be normal. However, when I turned off the engine, I did notice the compressor pulley would stop, but then move again (just a little). Followed by a high pitch sound of pressure being release from the compressor.

As for the e-fan, I'm assuming that's the fan, I've seen mention in other threads.. Since driving generates the needed air flow for the coolant and while idle the fan fails to.

How difficult is it get to the e-fan? Is it possible to go from the front to get to it? Or do you have to take out the radiator fan to get to it?

Again, thanks for the help.
 
#7 ·
following up

VOX87, just curious to know if you have found any luck with a good solution for this problem?

The symptoms sound identical to my issues (2000 SLT 4.7):
topped off refrigrant, blowing warm air while idling and cold when driving, compressor is making a clicking type sound, compressor pulley would stops when turning off the engine, but then move again a little, high pitch sound of pressure being release from the compressor.

Have you been able to get to the fan, or find any other issues, or any solutions? Your insight is deeply appreciated!
 
#8 ·
I'm trying to locate a fan.

Bought one from Car Quest and realized the shroud is totally different from the stock one. Tried some other places too (Auto Zone, Advance, Pep Boys), but no luck on an OEM.

Doesn't look like I can take the shroud off the stock and place it on the one I bought.

My shroud mount looks like this (in a generic sense), <@> , with bolts at the points of the lesser and greater symbols (left and right of the fan). I saw in another post, where someone had a different type of shroud on a 2000. Bolts on the top, bottom, and the sides.

From the reading I've done, it looks like I'll have to go through a dealer or somewhere online for the OEM part.

As soon as I can replace it, I'll follow up. Hopefully, some time this weekend. It's just too damn hot to deal with this warm air.
 
#9 ·
If the pressures are normal but the vent air is still not cooling at idle you might be overheating. Did you notice overheating at all?
 
#10 ·
I don't think its overheating. The temp gauge shows between the quarter mark and the temp symbol. Either way, the fan is gone and needs to be replaced.

Since none of the local stores were confident in their OEM reference, I finally found the OEM part# online today. Of course, I found several online places were the part was way cheaper than the local stores.

So, hopefully I'll have the part by this weekend and see if it corrects the issue.
 
#11 ·
Ok good just asking is all. Hope you get it fixed
 
#12 ·
Sorry.. I hope I didn't come across wrong. :)

I finally got the fan in today, but she's still blowing lukewarm air. I let it idle for about 15 mins and the cabin was still a bit warm. Temp gauge displayed normal temps (between the quarter mark and the temp symbol).

Not sure where to go from there.
 
#13 ·
vent air in a/c mode with the slider on cool and engine coolant temperature have nothing to do with each other
 
#15 ·
Yeah they have a lot to do with each other. The engine coolant is what goes through the heater core. Even if the blend door is closed to heat an overheated core will radiate heat into the a/c ductwork and cause undesired temps out the vents.

Thats why i asked the OP if he was overheating.

Since he isn't, my next step would be to check for kinks in
the refrigerant lines and to pull a vacuum on the system to check if there was moisture or too much lubricating oil in the refrigerant.
 
#14 · (Edited)
Double post somehow please delete this.
 
#16 ·
yeah, 215 deg water is ALOT hotter than 185!!!
 
#17 ·
This is the blend door...

this ones easy...forget about all the above posts

its the blend door in your air box...whats happening is that at speed sufficient air passes through the air box to keep the blend door pushed to one side. on idle the blend door springs back and you get a mixture of cold and hot air...despite the rotary temp knob being over to max cold

the blend door is controlled by a bowden cable from the rotary knob - not a fixed link...so when it sticks the slack is taken up in the cable...

solutions are difficult - try sticking a compressed air line down the vent and see if you can blow the muck out. take the rotary controller out and work the cable back & forth. finally worst case scenario is to take the dash apart and remove the air box for fixing

good luck...Chris
 
#18 ·
blend

thanks, Chris for this intrguing viewpoint and idea on an ongoing problem for me. Has Chris's suggestion worked for anyone else?

Any tips on going about forcing the blend door to sprng back open? chris, you mentioned using compressed air to backfeed through the vent ductwork -- which vent should I start with?

And exactly where in the vehicle does the air box / blend door exist?

Thanks folks!
 
#19 ·
*SNIP*
And exactly where in the vehicle does the air box / blend door exist?
It's about 6.5 hours inside your dashboard! Not for the queasy, you have to discharge the A/C lines as well to get the sucker out of the vehicle
 
#20 · (Edited)
I've noticed my A/C blows a tad warmer than I'd consider normal when I'm not moving. Usually only happens when outside temp is about 85 or higher, which it as been around Detroit lately. I'm sure the problem is just not enough air flow through the evaporator when not moving. My e-fan works fine, but I did remove the clutch fan.

Part of it could also be that the Durango evaporator is grossly undersized. I currently work with an ex Chrysler HVAC engineer. He worked on the Gen 1 Durango systems and was the lead engineer on the Gen 2 Durango automatic climate control system. He told me the other day that the Gen 1 Durango, at least the earlier ones, used the same A/C evaporator as the Dodge Omni!! Compare the interior volume of an Omni and a Durango and stop wondering why the Durango A/C is pretty mediocre.
 
#23 ·
*snip* He told me the other day that the Gen 1 Durango, at least the earlier ones, used the same A/C condenser as the Dodge Omni!!*SNIP
Thanks, that's why I posted the condenser pic.
... and it would've taken a lot longer to get a pic of the evaporator!
 
#21 ·
here's a pic of mine, I don't think an Omni could hold this even if you removed the engine.
 

Attachments

#22 ·
That's your condenser. The evaporator is the one inside your heater box.
 
#25 ·
Yeah, I've done that many times myself. I'm pretty sure the condenser was actually upgraded later on.
 
#26 ·
Thanks for your post, Brad81987. especially regarding the inadequate gen1 Durango evaporator.

I'm having some similar issues to yours: A/C blowing warm when over 85 degrees outside, when not moving.

I've been looking at the blending door in the airmix box being the possible issue, but I can help but think that the e-fan is at least part of my trouble. When running the A/C with shifter in Park, I lift the hood and listen to the e-fan; it's really noisy -- it sorta "whines" or "moans' ... it gets a little faster , then a little slower, every several seconds. It almost sounds like it's making contact with something else (the shroud perhaps?), but I look and see no obstructions. I'm totally a novice, but it seems to me like it's on its "last leg". I know that it doesn't turn on when: ignition is turned to operate all electronics (A/C, radio, windows, etc.) but is not turned on engine...is this common?

Additionally, similar to post by VOX87: When I turn the truck off, a few seconds later I hear a high pitch sound of pressure being release from the compressor. Maybe knowing this could help, too?


Have you had any results getting your Durango to cool off inside at the lower speeds? Would you mind asking for more about this from your friend who's a Dodge HVAC engineer?

Any and all thoughts are so appreciated!
 
#27 ·
I am having similar issues as posted in this thread. I do know that I was overheating a couple of weeks ago when we were driving to OBX. Traffic was horrible and the temps were near 100. As we sat waiting to cross the bridge my temp gauge just kept creeping up. I had to use the defrosters to keep it down some. Once traffic started moving again, everything was fine, except for us who were sweating to death!

I just had my a/c repaired and charged so I know this should not have been a factor but yet I was still getting warm air when at a stop or moving very slowly. Very frustrating after spending a few hundred dollars and being 300 miles away from home.

So I have come here to see what I can find and I found this thread, but I also looked at All Data to see what I could find. I found a TSB that states about a revised fan shroud, fan & fan drive. Here is the TSB:

NUMBER: 07-03-99

GROUP: Cooling

DATE: Nov. 5, 1999

THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 07-07-98, DATED NOV. 27, 1998, WHICH SHOULD BE REMOVED FROM YOUR FILES AND NOTED IN THE 1998 TECHNICAL SERVICE BULLETIN MANUAL (PUBLICATION NO. 81-699-99003). ALL REVISIONS ARE HIGHLIGHTED WITH **ASTERISKS** AND INCLUDE CHANGES TO PART NUMBERS, CHANGES TO THE PROCEDURE, AND CHANGES TO THE TIME ALLOTTED TO PERFORM THE REPAIR.
SUBJECT:
Engine Overheats In High Ambient Temperatures

OVERVIEW:
This bulletin involves installing a revised fan, fan drive, and fan shroud.

MODELS:
1998 - 1999 (DN) Durango

SYMPTOM/CONDITION:
Some Durangos may experience a high engine temperature condition (temperatures greater than 116°C. (240°F.)) when the vehicle is operated in stop-and-go traffic with ambient temperatures exceeding 32°C (90°F). The result from the high engine temperature may cause the following:

^ Engine Temperature Gauge To Read Higher Than Normal

^ Check Gauge Lamp To Illuminate

^ Warning Chime To Sound

^ Vehicles Equipped With Air Conditioning May Have The A/C System Disabled

NOTE :THE POWERTRAIN CONTROL MODULE (PCM) IS DESIGNED TO DISABLE THE AIR CONDITIONING SYSTEM WHEN ENGINE TEMPERATURES EXCEED A PREDETERMINED VALUE AND/OR THE A/C HIGH SIDE PRESSURE EXCEEDS 470 P.S.I. +/- 20 P.S.I.. THIS IS A NORMAL CONDITION DESIGNED TO PROTECT THE ENGINE FROM OVERHEATING AND FROM DAMAGING THE AIC COMPRESSOR. ONCE THE ENGINE TEMPERATURE AND/OR A/C HIGH SIDE PRESSURE HAS LOWERED, THE PCM WILL TURN THE AIR CONDITIONING SYSTEM ON.

DIAGNOSIS:
1. Examine the vehicle's cooling system for proper operation. The DRB III can be used to ensure that the engine temperature does not exceed 99°C (210°F) during normal operating conditions. If the engine temperature exceeds 99°C (210°F) during normal operating conditions, the cooling system must be inspected and repaired. Refer to the 1999 Durango Service Manual (Publication No. 81-370-9116), pages 7-9 through 7-20 for information regarding Cooling System Diagnosis And Testing.

NOTE :THIS BULLETIN ADDRESSES ENGINE OVERHEAT CONDITIONS THAT OCCURS ONLY IN STOP-AND-GO TRAFFIC WITH AMBIENT TEMPERATURES EXCEEDING 32aC (90°F).

2. If the vehicle's cooling system is operating normally and the customer identities that the vehicle exhibited the previously stated SYMPTOM/CONDITION, perform the Repair Procedure.

PARTS REQUIRED:

1 52027709 Fan, Cooling
1 52029767AA Drive, Fan
AR (1) **52029012AD** Shroud, Fan, Four Wheel Drive
AR (1) **52028614AC** Shroud, Fan, Two Wheel Drive

POLICY: Reimbursable within the provisions of the warranty.

TIME ALLOWANCE:
Labor Operation No: 07-20-01-94 **0.5 Hrs.**


I will check my e-fan first and then see what happens. But I wonder if this TSB is the cause of my problems. This has been an extremely hot summer for us, we don't usually have really high temps for extended periods of time. So my a/c doesn't usually get that kind of workout. Plus, we work 12 hour shifts, go in when it is cooler & come home when it is cooler, usually.

Well good luck to all of those who are having problems too. Hopefully one of the solutions listed fixes what ails your D.
 
#28 ·
Fan Clutch + Compressor

I ended up paying some serious "Stupid Tac" ($$$$ due to waiting too long to try and figure out /research the problem without the assistance of a mechanic -- this is STUPID)

After weeks of letting the problem go unchecked, I finally burnt up my compressor. I had the compressor repaired at the 'bargain price' of $900 (they said it was a good price becuase the parts came in a 'kit' which included: compressor, drier, andsome other stuff). Of course this included evacuation and recharge of the freon, etc. After this job was done, they still couldn't get the A/C to stay cool, and called me back that they discovered an issue with the fan clutch (only $150 to repair, labor and parts included).

The lump in my throat is that I really think that if I'd had the whole situation checked out sooner, they could have seen the fan clutch problem, and my truck would be running cool for only $150 instead of $1050. If I were you, I'd pay the diagnostic fee just to avoid the BIG expenses.
 
#29 ·
For what it's worth, I had very similar problems with my '99 as the OP. Heat gun readings showed air temps of approx. 70 degrees at idle and low 60's while cruising. Freon pressure was checked and found to be fine.

I finally traced it to a bad compressor clutch. For whatever reason, it simply would not hold properly and caused all kinds of odd cabin cooling problems, although there were no obvious signs of clutch problems. I installed a new one, and now the heat gun shows mid to low 50's at idle and mid to low 40's at cruise.

Hope this helps.
 
#30 ·
Did the compressor clutch make any kinds of noise? How did you end up diagnosing it as your problem?
 
#31 ·
For the vast majority of the time I was having problems, there was absolutely no noise coming from the clutch. It appeared to behave normally. It wasn't until about a week or so ago that it started howling when I'd start it in the morning, but it would go away after a few minutes. It howled regardless of whether the compressor was engaged or not. So I figured it was the clutch.

Unfortunately, you cannot buy the clutch from anybody (Autozone, O'Reilly, etc.) other than the dealer, and they want $250 for it. So I bought a new compressor and clutch from Advance Auto Parts for $225, removed the new clutch, and put it on the old compressor. I threw the new compressor on a shelf in case I ever need it.

The whole operation took about 1/2 hour, and it's rather simple. One bolt, two snap rings, and a puller. Make sure you swap the new clutch AND the new magnetic ring thingy behind it (cannot remember the name of that part for the life of me).
 
#32 ·
:rck:
 
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