A/C blowing hot air and heat always coming through the vents and floor?

JOE THE MARINE

MEMBER
2002 CHEVROLET BLAZER
4.3L
6 CYL
4WD
AUTOMATIC
191,000 MILES

Just recharged the A/C unit. When I am driving, I always get heat on the floor vent. And when I put the A/C on, all I get is very hot air blowing, not cold. I replaced all the vacuum lines in the engine area, checked all the actuators inside the dash, even used a vacuum tester to make sure they are all working. Once I hear clicking noise after I replaced the blend door actuator and looked and seen that it looked like it opened up or came apart. What a headache replacing that. So, I replace it again to see if this is the problem with the A/C unit not blowing cold air? I can do this again if I have to. Main reason I need the A/C working. Thanks for any help.

Sunday, May 26th, 2024 AT 9:31 AM

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

The actuator clicking is telling you it is not working but to be sure I would remove the temperature blend door actuator and move the blend door pivot by hand with the A/C system on to see if the vent air temperature changes. Are you sure the A/C system is getting cold? With the A/C system on, check the temperature of the outlet tube to the compressor at the firewall to see if it is cold. Please go over this guide:

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

Here is the location of the temperature blend door actuator so we can be on the same page. Also, the actuator must be calibrated:

Use the following steps to perform the calibration update:
1. Turn OFF the ignition.
2. Remove the battery positive voltage circuit fuse of the HVAC Control Module.

IMPORTANT: The module memory will not clear if the battery positive voltage circuit fuse is installed in less than 60 seconds.

3. Wait 60 seconds.
4. Install the fuse.

Check out the images (below). Please upload pictures or videos in your response to any problems so we can see what to help you with.

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Sunday, May 26th, 2024 AT 10:16 AM

JOE THE MARINE

MEMBER
86 POSTS

Thanks Ken. Did as you instructed, and it worked. The new blend door actuator worked from the chevy dealer and now I have cold air. Question, the blower doesn't blow as hard as it use to from the vents, could there be a blockage somewhere in the heater box or somewhere else? The air that comes out is like the fan is on medium, not on the high blower. Ask exolain b4, the blower mower is new and the HVAC panel is new too. I get answers that the heater box has a leak is it somewhere and I have to remove the dash to seal up and holes around the box. I would like to see if a door is being blocked somewhere before I remove the dash. What do you think and what's your ideas on this issues? Thanks for any help so far and God bless the work you past off to all the questions on this site.

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Friday, June 14th, 2024 AT 2:16 AM

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

Glad you could get it fixed, thanks for letting us know. Sorry, we only handle one problem per thread, please post your new question here, you must be logged in.

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

Cheers, Ken

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Friday, June 14th, 2024 AT 10:57 AM