Common questions

Why does the AC light blink and then go off?

Why does the AC light blink and then go off?

Information for Vehicles with HVAC Control Module A/C and Recirculation Indicators Flashing Some customers may comment that the Air Conditioning (A/C) indicator on the Heating Ventilation and Air Conditioning (HVAC) Control Module flashes then turns off after they press the A/C button.

Why is the a / C blinking ON MY 1992 Chevy?

Some owners of 1991-1992 C/K vehicles may comment that the A/C letters in the middle of the control head face are flashing. The HVAC control system used on 1991 and 1992 C/K vehicles incorporates a low A/C charge warning system.

Why is my a / C light flashing on my GM car?

GM has issued a technical service bulletin #09-01-38-004: INFORMATION FOR VEHICLES WITH HVAC CONTROL MODULE A/C AND RECIRCULATION INDICATORS FLASHING. The bulletin applies to the following vehicles: The A/C light is designed to flash and disallow A/C operation if any of the following conditions are present:

Why is my air conditioner not working in my GMC Acadia?

Consult the appropriate vehicle Service Information (SI) for detailed HVAC Description and Operation: • Ambient Air Temperature is too low (if equipped with Ambient Air Temperature Sensor) • Vehicle voltage less than 9.5 volts • Refrigerant Pressure too low • Refrigerant Pressure too high • EngineCoolantTemperature too high • Engine is not in RUN

GM has issued a technical service bulletin #09-01-38-004: INFORMATION FOR VEHICLES WITH HVAC CONTROL MODULE A/C AND RECIRCULATION INDICATORS FLASHING. The bulletin applies to the following vehicles: The A/C light is designed to flash and disallow A/C operation if any of the following conditions are present:

Some owners of 1991-1992 C/K vehicles may comment that the A/C letters in the middle of the control head face are flashing. The HVAC control system used on 1991 and 1992 C/K vehicles incorporates a low A/C charge warning system.

Why does my AC blink when there is a low charge?

If a low charge is detected, the control head will not allow the compressor to engage and the A/C letters in the middle of the control head face that usually signity A/C operation will blink. The HVAC control head determines a low charge by monitoring the circuit from the pressure cycling switch.

Why is the AC Light not working on my GMC Acadia?

Finally got the Car yesterday after 4 days in the Garage (AC and steering growling job). They have recovered all old gas and put a new one using the new advised pressure as per GMC’s bulletin. They also have re-programmed the computer box. As per the QA guy, Due to very hot climate here, GMC had released new bulletin to fix this issue.

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Ruth Doyle