No heat from vents

Hi and thanks for using 2CarPros.com.

A traditional type heater control valve does not exist on this vehicle. I did not think it did. So, I checked through all my manuals and temperature is controlled via the blend door, which you said you repaired.

Here is a general link that discusses possible causes of no heat:

https://www.2carpros.com/articles/car-heater-not-working

Next, with the engine warm, the heater control knob on heat, do both heater chore hoses get hot under the hood?

I was able to find a technical service bulletin (TSB) related to temperature issues. Its focus is on the blend door actuator. Take a look through it. All attached pictures correlate with the TSB.

The blend door control lever moves freely, but the blend door does not operate.

A bushing that fits on the lever may have a broken tab/clip, -arrows-, as shown.

This tab/clip may cause the bushing to fall out of the fresh air housing which can result in the door becoming inoperative and result in undesired air temperature.

Tip:

In the past the entire fresh air housing was replaced because the bushing was not available as a separate part. The bushing is now available as a separate part. The bushing can be accessed from under the center console.

Remove the panels near the foot wells at the passenger side of the console, -arrows-, as shown.

See Repair Manual, Body-Interior, Repair Group 68 - Interior Equipment for removal procedure.

This will expose the location of the control lever, -arrow-, as shown.

Re-bolt a new bushing onto the lever, -arrow-, as shown.

Re-insert the bushing with lever onto the blend door until it is firmly secured in the housing.

Reinstall panels.
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I was also able to find how to adjust the cable. Picture 7 correlates with these directions,

TEMPERATURE FLAP CABLE, INSTALLING AND ADJUSTING
Cables, Installing And Adjusting

Temperature flap cable, installing and adjusting
Prerequisites:

-Heating and ventilation controls are installed.
-Connecting duct removed.

Adjusting

-Turn temperature rotary control knob to left onto stop.
-Attach center wire of cable -1- to the temperature flap lever -2-.
-Push temperature flap lever -2- to stop - arrow A- and secure outer cable -1- with clip -3-.
-Turn temperature rotary control knob to left and right onto stops.
- When turning the rotary control knob, both end stops must be reached.

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Let me know if any of this helps or if you have other questions.

Take care,
Joe

HI and welcome back.

Thanks for that information. I am sure it will help someone. Also, the corrosion is common to a degree. I questioned if something was plugged when I asked if both heater core hoses were hot. As far as coolant on this vehicle, I agree with what you said. Keep it the same. The only thing I would consider is a universal G-O5 coolant that is compatible with what is in the vehicle.

Again, thanks for letting us know. And good advice to everyone is to make sure to use the manufacturer's recommend coolant, especially, GM vehicles. Never mix green traditional coolant with the factory DexCool (pink) coolant. It makes a mess.

Take care and I hope you have a good Thanksgiving.

Joe