Answer
Jul 16, 2025 - 09:52 AM
I feel you — trying to find that inside ambient (in-cabin) temperature sensor on a 2004 Sierra can be a headache. There’s a lot of mixed info out there, and even GM support seems to be leaning on generic diagrams these days.
But yes — this manual does show exact HVAC component locations tied to your trim level and options (manual vs. automatic climate control, etc.).
For most 2004 Sierra 1500s with auto climate control (dual-zone), the in-cabin temperature sensor is located behind the small grille on the driver-side dash trim, near the steering column, usually close to where your left knee would be when seated. It’s part of a little aspirator setup — a tiny fan draws cabin air over the sensor.
If your truck has manual HVAC, it may not have a dedicated in-cabin temp sensor at all — just uses blend door actuators with fixed mapping.
The manual provides:
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Exact sensor locations by HVAC system type
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Connector views and wiring pinouts
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How to test and remove the sensor without tearing apart the dash
So yeah, the manual should save you (and your mechanic) from ripping up the interior blindly.
