AC not working?

Tiny
SSXT
  • MEMBER
  • 2003 TOYOTA HIGHLANDER
  • 3.0L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 210,000 MILES
Hi, the A/C stops blowing cold air when driving on the highway at 75 or more MPH, which is about 3,000 RPM. Outside temperature was 85°. If I slow down to about 65 MPH it starts to blow cold again. My 1997 Camry with the same 3.0 (1MZ-FE) engine had the same issue. Works fine around town. Thanks.
Tuesday, June 18th, 2019 AT 7:54 PM

13 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,363 POSTS
Hello,

It sounds like the evaporator is icing up due to lack of charge. To confirm here is a guide to help confirm the failure:

https://youtu.be/uZrQCGwXfek

Please run down this guide and report back.
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Thursday, June 20th, 2019 AT 1:53 PM
Tiny
SSXT
  • MEMBER
  • 8 POSTS
Hi,
As the compressor clutch (?) Was making noise too, I just replaced it and reloaded the refrigerant. Haven't had a chance to test it on the freeway (speed limit is only 70 near me). Will review your link if reoccurs on my next road trip. Thanks for the information.
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Wednesday, June 26th, 2019 AT 11:02 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,363 POSTS
Hmm, it could be overcharged if the compressor start making noise after a bit. Can you please shoot a quick video with your phone so we can hear the noise, that would be great. You can upload it here with your response.
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Wednesday, June 26th, 2019 AT 11:26 AM
Tiny
SSXT
  • MEMBER
  • 8 POSTS
Ken,
Already swapped the compressor w/a lower-mileage used one (seems OEM used is better than aftermarket new), which is working fine - so far. So no noise to record. Thanks
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Wednesday, June 26th, 2019 AT 11:29 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,363 POSTS
Nice work, we are here to help, please use 2CarPros anytime.
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Thursday, June 27th, 2019 AT 10:18 AM
Tiny
JERRY AUGUST
  • MEMBER
  • 2 POSTS
  • 2003 TOYOTA HIGHLANDER
  • 2.3L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 180,000 MILES
A/C starts working okay after awhile it stops blowing cold air. Turn the system off for about five minutes. Turn the system on A/C starts cooling again. Also, the switch light for in and outside air will not go off. If you do have the switch set for outside air and driving the light will come on. Cannot turn light off.
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Thursday, June 27th, 2019 AT 10:55 AM (Merged)
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,363 POSTS
Hello,

This sounds like you have a compressor clutch that is going out. When the system is blowing warm air check the front of the compressor to see if the clutch is engaged. If not check for power at the compressor.

Here are a couple of guides that will help you confirm power or not:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

and

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Please run this test and get back to us so we can continue helping you.

Cheers, Ken
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Thursday, June 27th, 2019 AT 10:55 AM (Merged)
Tiny
MBFETSKO
  • MEMBER
  • 6 POSTS
  • 2002 TOYOTA HIGHLANDER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 100,000 MILES
All of a sudden my vents started blowing hot air, despite having the AC on and the thermostat turned all the way to cold. I thought it was a bad engine thermostat and, while troubleshooting that problem, found that the water pump had failed. I have replaced the water pump, thermostat and "flushed & filled" the cooling system - but the vents are still blowing hot air. The AC/heat fan motor is working properly, the air can be directed to the various outlets (floor, dash, defroster and all mixes) as normal, the AC switch is working and the compressor is operating properly. Any ideas?
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Thursday, June 27th, 2019 AT 10:55 AM (Merged)
Tiny
JASONRAY
  • MECHANIC
  • 213 POSTS
Something's going on with the 'blend door' or the actuator for that door. This door is inside the evaporator case but the actuator will be mounted to the outside of the case. The control (hot to cold knob) is what controls the actuator. Either the control knob is not sending the info to the actuator or the actuator itself isn't working and it's stuck in the HOT position.
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Thursday, June 27th, 2019 AT 10:55 AM (Merged)
Tiny
BOBPOWER
  • MEMBER
  • 1 POST
  • 2002 TOYOTA HIGHLANDER
  • 150,000 MILES
Thought the a/c air flow was not cold, cool, but not cold. Added some ac pro air flow, temp. Maybe worst but I do feel the air flow is cold at times and then warms up and then back to warm. Get it. I did look at the ac compressor and the clutch does cycle on and off, some times 20 to 30 sec. Some time little longer. Does the cycle on and off relate to air temp. Being cold to cool? I want to say no but can look a little harder. I know you get this all the time but I can pay if I heard some good news.
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Thursday, June 27th, 2019 AT 10:55 AM (Merged)
Tiny
CJ MEDEVAC
  • MECHANIC
  • 11,005 POSTS
Go to "you tube"

type in "a/c pro recharge " in the search box

this may take a little time. It may be helpful

look at the 2nd - 5th videos

maybe you missed something?

If trying these methods just-ain't-a-workin'.I would suggest seeking more professional help. You don't wanna make things worse

the medic
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Thursday, June 27th, 2019 AT 10:55 AM (Merged)
Tiny
DAVID KIM PAM
  • MEMBER
  • 1 POST
  • 2002 TOYOTA HIGHLANDER
  • AUTOMATIC
The air conditioner blow in cold and hot air intermitently
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Thursday, June 27th, 2019 AT 10:55 AM (Merged)
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
It may be your temp servo is n't working right but have the a/c performance tested as it may be low on Freon or it's icing which requires evacuation. As well as a new drier in system.
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Thursday, June 27th, 2019 AT 10:55 AM (Merged)

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