OFF Mode

1999 GMC Forward Control 5.7 R, AutomaticSECTION OFF Mode
WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

Press the passenger temperature knob to turn off the HVAC control module. When the vehicle is moving, air flowing over the vehicle increases the air pressure just ahead of the windshield. This forces air into the ambient air into the HVAC module and out through the floor and windshield outlets. Since the A/C compressor is not running, the incoming air may be warmed but not cooled. Recirculation is not adjustable in OFF mode.

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.