Why does my Chevy Trailblazer have a cowl hood?

The blower motor will not operate to supply the ventilation air, but the high pressure air in the cowl area (the same type that a cowl hood takes advantage of) is what makes the airflow. It’s got to do with interior ventilation and supplying the interior with fresh air while underway.

Why is my defroster not working on my car?

A control switch on the dash can fall apart allowing the vacuum to escape and not reach the servos. A defroster can also fade when traveling up a hill but then return once the grade is overcome which is a signal the vacuum check valve has failed.

Where is the actuator on a Chevy Trailblazer?

I usually sneak them in and out through the driver side underdash area. Sometimes it goes ok (but still a pain in the ass), other times they fight me tooth and nail. I can dig up the service procedure out of the manual if you want to PM me your email addy.

Why does my trailblazer not shift out of Park?

03 trailblazer starts/runs but will not shift out of park with brake applied. feels like problem is in shifter because button on shifter will not depress to allow it to move. Is there a part in shifter that is prone to failing. also any pictures diagrams could be helpful.

Why is the vent control on my 2002 Silverado not working?

Vent control 2002 Chevy Silverado won’t switch between floor, defrost or “main”. It is stuck on “main”. Do I need to replace actuator or is there a vacuum leak somewhere?

What to do if your GM fan won’t defrost?

See if this fixes the problem. Many of GM’s AC control heads have a built in reset feature that when power is removed and then applied it will go through a cycle that activates all the vent doors and mode doors. It’s worth a try.