A/C and vents not working properly

Tiny
CHRISTARA
  • MEMBER
  • 2004 TOYOTA SEQUOIA
  • 4.7L
  • V8
  • 2WD
  • AUTOMATIC
  • 200,000 MILES
I just put in a new A/C compressor clutch and blower motor. I have 2 questions:
1. Why is there no air and the A/C light is blinking when A/C is turned on?
2. Why is air blowing in the back vents but not the front vents?
Sunday, July 26th, 2020 AT 10:14 AM

5 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,864 POSTS
Hi,

I need to confirm something. First, do you mean the blower motor isn't working on the front? Does the A/C cool the air coming from the rear vents?

There are two different blower motors on this vehicle. One is front and one is rear. See the attached two pics. Which one has been replaced?

Next, if the light is flashing, there is a fault in the system at some point. What may need to be done is to have the computer scanned to identify diagnostic trouble codes related to the HVAC system. This will point us in the right directions.

Let me know the answers to my questions so I have a better understanding of exactly what is happening and what was replaced.

Take care, and I'll watch for your reply.

Joe
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Sunday, July 26th, 2020 AT 1:48 PM
Tiny
CHRISTARA
  • MEMBER
  • 3 POSTS
I just replaced the blower and blower fuse. The rear blows air but not cold and the front barely blows at all.
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Sunday, July 26th, 2020 AT 2:03 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,864 POSTS
Hi,

Was it the front blower motor, under the dash in the front? Also, can you hear the blower motor running at different speeds even though there is little air flow?

For the A/C not blowing cold, is the new compressor clutch engaging and cycling on and off?

Joe
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Sunday, July 26th, 2020 AT 2:33 PM
Tiny
CHRISTARA
  • MEMBER
  • 3 POSTS
I replaced the front blower motor.
Yes, I can hear the blower and it's kinda noisy.
The new clutch is cycling on and off.
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Sunday, July 26th, 2020 AT 4:27 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,864 POSTS
If the clutch is cycling on and off, then it should be producing cold air unless the air temperature door actuator isn't allowing the cold air to enter.

Do me a favor. Record the sound of the blower motor so I can hear it. Also, I'm attaching diagnostics for checking the air mix actuator. Make sure it is working.

________________________________

2004 Toyota Truck Sequoia 2WD V8-4.7L (2UZ-FE)
Air Mix Servomotor
Vehicle Heating and Air Conditioning Air Door Actuator / Motor Testing and Inspection Component Tests and General Diagnostics Air Mix Servomotor
AIR MIX SERVOMOTOR
AIR MIX SERVOMOTOR

INSPECTION

see pic 1

1. REMOVE AIR MIX SERVOMOTOR
a. Disconnect the connector.
b. Remove the 3 screws and servomotor.

2. INSPECT AIR MIX DAMPER POSITION SERVOMOTOR
Refer to Heating and Air Conditioning; Testing and Inspection.
3. INSPECT AIR MIX SERVOMOTOR CIRCUIT
Refer to Heating and Air Conditioning; Testing and Inspection.
4. INSTALL AIR MIX SERVOMOTOR
Refer to Heating and Air Conditioning; Testing and Inspection.

_______________________________

Since the A/C compressor is cycling, there is enough low pressure in the system to operate. However, if it is too low on Freon, it really won't cool the vehicle. Here is a link for recharging the system just in case you haven't already. Also, I attached an additional link that reviews the most common causes of an A/C not cooling or very weak.

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

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

______________________________

I do have one last question. What prompted you to replace the blower motor and the compressor clutch? They are usually not done at the same time. I'm just curious to know and it may help me diagnose the issue.

Let me know.
Joe
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Sunday, July 26th, 2020 AT 8:37 PM

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