AC not giving cold air

Tiny
DESI2P
  • MEMBER
  • 1999 TOYOTA SIENNA
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 114,000 MILES
I had done AC recharge. Cold air worked about a week only. The guy who recharge it saying its leaking from rear. He also said there is still some juice left in it, so it means it did not leak all of it. He did show me the leak, which was about only 2 drop on the line. He said, I need to replace the rear AC coil. My question is, if the leak is in the rear, should the front one work? Please advise if I really need to replace the coil or is there way to seal it.
Monday, June 21st, 2010 AT 3:10 PM

16 Replies

Tiny
MHPAUTOS
  • MECHANIC
  • 31,937 POSTS
Hi there,

The refrigerant feeds both systems, you will have to get this leak repaired. Here are two guides to help us find the problem and fix it.

https://www.2carpros.com/articles/air-conditioner-leak-detection

and

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

Please run down these guides and report back.

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Monday, June 21st, 2010 AT 6:51 PM
Tiny
KISSAB16
  • MEMBER
  • 1 POST
Thank you for this post I had to get a new AC line which rubbed through cost me $230.00 the guides are excellent.
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Tuesday, September 3rd, 2019 AT 3:30 PM
Tiny
TAMARAJP
  • MEMBER
  • 1 POST
  • 1999 TOYOTA SIENNA
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 150,000 MILES
My car's heater wasn't working so I took it in to get it looked at, they quoted $800 so I said skip it, I live in San Diego and it wasn't something I needed very often. Driving home from the repair place I realized that my a/c was blowing hot air. Somehow when they looked at the heater to diagnose the problem they fixed the heater issue but now my air doesn't work and my heater is always on. What did they do? I figure it must be behind the dash because that's where they were working and I'm hoping that means it won't be difficult to fix?
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
CARADIODOC
  • MECHANIC
  • 34,331 POSTS
Without being able to see it, of course this is only a guess, but based on your description, it sounds like the problem is with the temperature door and its actuator. Unfortunately that also means there's a computer involved. Computers on newer vehicles cause a real lot more problems than the non-existant "problems" there are used to solve. Most likely, in their diagnosis, they moved the temperature door to see how the computer would respond, or if it even would do anything. To verify this, you can check if the AC compressor is running and if the metal pipe going to the firewall is cold. If that pipe is cold, the AC is still working. It's just that the temperature door is set to "Hot" and has to be manually moved back to "Cold".
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+1
Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
KOHLLINK
  • MEMBER
  • 80 POSTS
  • 1999 TOYOTA SIENNA
A/c light blinking. Jumped the compressor 37 psi low and 170 high side. When a/c is engaged with the a/c button the compressor comes on a few seconds then gets overridden by something. Sensor? Or a/c amplifier gone bad? Is here a low pressure sensor that I need to check? Where is it located?
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
This will not be something you will have much luck finding. The compressor has an RPM sensor that the control head monitors. If the compressor stops or slows down for any reason, the control head will shut the system off. Very difficult to determine what caused it.
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
KOHLLINK
  • MEMBER
  • 80 POSTS
Is the compressor shot? The rpms do slow down when the compressor is engaged.
.
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
AOCTAJR
  • MEMBER
  • 2 POSTS
  • 1998 TOYOTA SIENNA
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 147,000 MILES
A/C doesn't work when car is running but will work when the engine is idling.
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
DAVE H
  • MECHANIC
  • 13,384 POSTS
Start by checking the R134 level is correct
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
AOCTAJR
  • MEMBER
  • 2 POSTS
Yes, refrigerant level is good. No bubbles on viewer. A/C work's well when engine is idling. When moving, A/C stop's working, indicator's still on but warm air coming out of vent.
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
ITSCARBONY
  • MEMBER
  • 1 POST
  • 1999 TOYOTA SIENNA
  • 65,000 MILES
The ac of my toyota siena works when you put it on first thing in the morning, then after about 15 mins it cuts off and the ac stops working but the ac light keeps on
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Have you checked the freon level, compressor operations if battery voltage is applied, compressor relay etc?
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
KOHLLINK
  • MEMBER
  • 80 POSTS
  • 1999 TOYOTA SIENNA
Where can I get a rpm sensor for a 1999 Toyota Sienna. I checked the ohms on the ac compressor rpm sensor and not getting any reading. I think its bad.
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
DOCFIXIT
  • MECHANIC
  • 18,828 POSTS
Was OHM reading taken from term 1 to 2 65-125 ohms if open according to Toyo replace compressor. Part not replacable
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
KOHLLINK
  • MEMBER
  • 80 POSTS
I got a new compressor and checked the ohms. I got a good reading on the sensor. Thank you.
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)
Tiny
DOCFIXIT
  • MECHANIC
  • 18,828 POSTS
Bummer they are made that way back in 90's sensor was replaceable
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Tuesday, September 3rd, 2019 AT 3:30 PM (Merged)

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