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Any idea why AC only blows cold when moving?

Discussion in 'General Tech and Maintenance' started by FLounder, May 9, 2011.

  1. FLounder

    FLounder power hungry VIP

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    My fiancees 03 RSX base has some weird AC issues. The AC blows hard all the time, but when you are sitting at idle at a redlight or something it goes from cold to lukewarm. As soon as you get moving it gets cold again.

    I popped the hood and noticed that when the AC compressor kicks on that it almost stalls the engine. And noticed that the second fan on the radiator never came on (although i dont think thats related). I dont really know much about AC systems, but im wondering if the clutch on the compressor could be bad or the compressor itself, or am i barking up the wrong tree???

    any help is appreciated :D
     
  2. RHDism

    RHDism Right Hand Drive guru

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    You nailed it...a/c clutch on its way out. Higher rpm causes the clutch to engage thus pumping refrigerant and delivering cool air.
     
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  3. CAFROG

    CAFROG Honda Minion VIP

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    Driving also cools down the condenser so it might be the condenser fan isn't turning on. Not saying it isn't the pump but mess with the fan first b/c switching the pump means discharging and charging the freon.
     
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  4. B16RacerN2NR

    B16RacerN2NR Working Hard VIP

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    Higher RPM does not cause the a/c compressor clutch to engage. IDK who the fuck told you that...

    I'm going to lead towards the condenser fan being the issue as well, since you already stated it's not coming on and this problem only happens at idle.
     
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  5. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    :rimshot:
     
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  6. FLounder

    FLounder power hungry VIP

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    thanks guys! rep to all!

    im about to go down to the garage and see if i can get that fan working and do a tune up on the car. ill post up whatever i figure out with the AC.
     
  7. FLounder

    FLounder power hungry VIP

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    the fan motor is definitely bad. have a new one coming later today.
     
  8. RHDism

    RHDism Right Hand Drive guru

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    Actually there racer guy, he stated , "as soon as you get moving" it gets cold again.
    Where did he state its not coming on?
    Just pop into the thread and drop an F bomb :confused:

    Higher rpm will assist the clutch to completely engage,(I apologize for not being more clear on that) and is likely the culprit.
    Unlikely for a faulty fan to cause the engine to "almost stall " at idle,(a faulty compressor will) although it could cause the cabin air to become luke warm as stated, due to the fact the refrigerant passing through the condensor is losing its refrigerant temp. Like Carfrog stated,the wind from the car in motion is assisting the condensor to cool. At this point, could be one or the other, possibly both. There are many components in an A/C system that can cause the system to not function as desired.

    Report back with results.
     
  9. CAFROG

    CAFROG Honda Minion VIP

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    From my knowledge.....the clutch on the pump turns on/off is not based on rpm. You turn the a/c on and you can feel that the clutch has engaged.....even at idle.

    Plain and simple......these older Hondas/Acuras have small condensers. They can cause warmer temps in city driving vs hwy driving. Anyone with a/c in these old Hondas can contest to that fact. The wind cools the condenser.....which cools the freon....so colder air. If the fan isn't engaged.....makes total sense to check it first. Its cheaper to fix and IMO is a problem
     
  10. B16RacerN2NR

    B16RacerN2NR Working Hard VIP

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    HIGHER RPM DOES NOT HELP THE A/C CLUTCH ENGAGE. I don't know how else to tell you that.

    He didn't have to say the fan wasn't coming on. Anyone who knows how to diagnose problems could see from his symptoms that it was a cooling of the condenser problem. Gee, what happens when the car gets moving again? Oh that's right, air flows through the condenser. There's a reason it's in FRONT of the radiator. What would pull air through the condenser while the car is still? Yup, the condenser fan...

    The "stall" is on damn near all cars that have A/C compressors with clutches. The OP may just not have noticed it before but just happened to notice it since he was looking for any problem that could have been associated with his problem. Happens all the time with customers at my job.

    But according to you, this "faulty" compressor only engages at higher RPM so why or how is it causing this "stall" at idle? This is where misdiagnosis will bite you in your ass ;)

    Anyway, mdpsEG, glad you got this problem taken care of. The weather is starting to get fucking hot lol.
     
  11. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    In the original post...
     
  12. RHDism

    RHDism Right Hand Drive guru

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    mdpsEG must enjoy the response he is getting on this one.

    Wether its agreed that an rpm increase can assist the function of an a/c compressor or not, we have certainly steered him in the right direction to get a solution to the problem.

    Good luck and let us know what the solution was.
     
  13. B16RacerN2NR

    B16RacerN2NR Working Hard VIP

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    He already said what it was. It was in fact, the condenser fan. There's nothing to agree or disagree on if rpm assist in getting the ac clutch engaged because the answer to that was already stated :)
     
  14. FLounder

    FLounder power hungry VIP

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    the fan is definitely bad, yes... i had to order a new one, and i havent put it in yet. im hoping that is the only problem. it looks like the clutch is engaging but i am surprised by how much it affects the motor when it comes on.

    it will probably be until this weekend for me to install the new fan. ill let you guys know if it solves the problem.

    and thanks for all the input :p
     
  15. CAFROG

    CAFROG Honda Minion VIP

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    :shrug: Never got an update to the solution :shrug:
     
  16. FLounder

    FLounder power hungry VIP

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    oops! my bad!

    it was the fan all along. installed a new fan motor, and no more problems. AC works great even in this summer heat.
     
  17. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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  18. CAFROG

    CAFROG Honda Minion VIP

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    Vindication! lol

    Glad its all fixed :thumbsup:
     
  19. Lian3rd

    Lian3rd New Member

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    Good day!

    I have the same problem. Ac blows cold only when the car is running... my fan works perfectly and the clutch engages also when the ac is on. Any ideas?
     
  20. CAFROG

    CAFROG Honda Minion VIP

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    My guess is a small condenser. I've never been in a car (even deisel pick-ups) that felt the same AC temp in the city vs. highway. Civic little condensers makes this situation worse.

    But if temp at a stop is really bad and running is almost kind of cool, there could be a leak and it's low on freon.
     
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