A/C not blowing air?

Tiny
JUANEMMANUEL
  • MEMBER
  • 1998 BUICK RIVIERA
  • 3.8L
  • V6
  • 2WD
  • AUTOMATIC
  • 175,000 MILES
I press the button to turn on the A/C and nothing happens at all. The buttons on the climate control are all lit up and the small screen shows numbers as well. But no air comes out at all, hot or cold. The compressor does turn on, and the refrigerant pipe feels really cold to the touch. I already checked the corresponding fuses and the compressor relay and they're all good. I bought another climate control unit just to rule that out, but still no change at all. Any info is appreciated.
Saturday, August 24th, 2024 AT 12:39 PM

13 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Can you hear the blower motor running when the system is on? If not, you could have a bad blower motor and if so, it sounds like the mode actuator is not working?

This guide can help:

https://www.2carpros.com/articles/low-or-no-air-flow-from-vents

Here is how to test the blower motor wiring and I have included the blower motor and mode actuator location so you can check it out.

https://www.2carpros.com/articles/how-to-test-an-automotive-hvac-system-blower-fan-motor-a-detailed

Check out the images (below). Please let us know what happens.
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Saturday, August 24th, 2024 AT 6:41 PM
Tiny
JUANEMMANUEL
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  • 63 POSTS
No, I can't hear the fan at all. I put in a new blower motor about 5 years ago. I was reading it could be the blower resistor. Do you think that could be the issue?
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Saturday, August 24th, 2024 AT 7:17 PM
Tiny
KEN L
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The blower resistor only comes into play on the lower speeds. Does the fan motor work at high speed? If not, I would use the guide above and if you have power and ground replace the blower motor again.
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Sunday, August 25th, 2024 AT 9:27 AM
Tiny
JUANEMMANUEL
  • MEMBER
  • 63 POSTS
Okay, so, I removed the blower and I hooked it to a battery and it turned on. I attached the video.
Also, I forgot to mention that the A/C doesn't turn on at any speed, high or low.
I tried putting a test light on the blower connector and turning on the A/C but I didn't get any power. However, I'm not 100% sure if it's because I wasn't getting a good ground. But it seems like there might be a short somewhere, correct?
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Monday, August 26th, 2024 AT 6:43 AM
Tiny
JUANEMMANUEL
  • MEMBER
  • 63 POSTS
Another thing I was curious about is this fuse box located under the hood in my 1998 Riviera. There's 2 relays labeled Cooling Fan #2 and Cooling Fan #3. Below those there's one labeled just Cooling Fan.
I assume Fans #2 and #3 mean the radiator fans, but what about the one just labeled Cooling Fan, could that be for the A/C blower?
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Monday, August 26th, 2024 AT 7:01 AM
Tiny
KEN L
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You can check the ground by using this guide with the test light connected to power.

This guide can help:

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

I would also check the HVAC blower motor fuse and the IP 1 fuse in the right rear fuse panel. I have also included the other five fuses that run the system in the images below that need to be checked as well and their locations.

If all fuses are good and the ground is good, I would replace the Heater and AC programmer behind the right side of the dash. I also included the complete HVAC wiring diagrams. Check out the images (below). Please let us know what happens.

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Monday, August 26th, 2024 AT 8:22 AM
Tiny
JUANEMMANUEL
  • MEMBER
  • 63 POSTS
Okay, so, I checked the HVAC Blower Motor fuse (30a) and the IP fuses 1 and 2 (10a) and they're all good. Also, I should mention that I bypassed the heater core a long time ago. Since there's no coolant running through it, I don't have heat, which is fine because it's hot basically all year round where I live. I will look again into testing for ground and current at the connector.
Is there a way to test the resistor? Someone told me that a bad resistor can also cause for there to be no air from the vents. Thanks
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Monday, August 26th, 2024 AT 12:56 PM
Tiny
JUANEMMANUEL
  • MEMBER
  • 63 POSTS
So, I checked all the fuses labeled Cooling Fan under the back seat and inside the cabin and they're working fine.
I checked the power again at the blower motor connector, and it is getting some.
However, when I disconnected the blower motor resistor, I found that one of the wires is burned. And the corresponding terminal on the resistor itself looks black as well. On the backside of the resistor, there's some green powder, similar to the buildup on battery terminals. There's some videos below. I am going to replace one of the connectors on the resistors, but just visually would you recommend putting a new resistor as well?
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Monday, August 26th, 2024 AT 5:10 PM
Tiny
KEN L
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Yep, you found the problem. Thanks for the videos, this will need to be repaired before the blower motor will work again, replace both the connector and the resistor.
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Tuesday, August 27th, 2024 AT 9:10 AM
Tiny
JUANEMMANUEL
  • MEMBER
  • 63 POSTS
Problem Solved***
I put in the new resistor and connector and AC works like a charm. However, whenever the AC is on, there's a loud squealing sound coming from the blower area. When I turn off the AC, the sound stops, so I'm pretty sure it's the blower itself. It safe to spray some WD40 on the blower bearing to quiet it down?
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Sunday, September 1st, 2024 AT 8:49 AM
Tiny
KEN L
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Yep, the loud squealing noise is the blower motor which is common, WD40 might help. If not you will need a new one.
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Sunday, September 1st, 2024 AT 10:53 AM
Tiny
JUANEMMANUEL
  • MEMBER
  • 63 POSTS
So, I replaced the motor and the sound went away. But now I have another problem. Sometimes I turn off the car and the blower stays running. A couple days ago, when I got off work I went to my car and when I opened the door, I heard the fan running, while the car had been off for hours. I don't know how long it was running but this is something that was not happening before I changed the blower motor and the resistor. What could be the cause? Thanks
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Saturday, September 7th, 2024 AT 12:51 PM
Tiny
KEN L
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Good job on the fix, let's start a new thread for the new problem please.

https://www.2carpros.com/questions/new

Cheers, Ken
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Sunday, September 8th, 2024 AT 11:01 AM

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