Heater and A/C

1999 CHEVROLET TAHOE
169,000 MILES • 7.5L • V6 • 4WD • AUTOMATIC
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JOE SOLIZ
  • MEMBER
  • 2 POSTS
Blows hot air without being on, barely blows hard air and doesn't blow cold air.
Jan 5, 2021 at 3:52 PM
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KASEKENNY
  • Experienced Mechanic
  • 18,907 POSTS
Just to be clear, the blower is blowing all the time and does not change speed? Nor does it blow hot or cold, just warm air?

If this is the case, I suspect you have two issues. Let's start with the blower motor. Here is a guide that will help with this:

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

We need to go to the blower and check for voltage while we are changing the speeds. If it is not changing then we need to replace the relay as it is most likely failed. I attached the info below on this including the wiring diagram.

Let me know what questions you have and we can go from there. Thanks
Jan 7, 2021 at 7:21 AM
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