Erratic A/C fan?

sburton0sburton0 Member Posts: 1
edited October 2015 in Pontiac
I have a 2004 Grand Prix GTP. The A/C gets perfectly cold, but sometimes it doesn't blow any air. Strangely, when I hit the control panel next to the fan speed knob it starts blowing. However, this is only temporary and the fan speed is still erratic--it constantly slows down and speeds up without touching the knob. Does anyone know what could possibly be causing this? Thanks.


  • imidazol97imidazol97 Crossroads of America I70 & I75 Member Posts: 26,599
    Is your fan an automatic fan with a temperature controlled system? In other words you have 6 or seven speeds that you can pick--or is it a 4 speed fan with just 3 speeds and HI, e.g.?

    If it's an automatic fan for a system where you set a temperature and the system tries to maintain that when set on AUTO by increasing or decreasing the blower speed, it's likely your blower control module (BCM). These are available aftermarket. I do not know how difficult yours would be to access and replace. It will be located near the end of the power cord to the fan blower itself.

    If it's a manual control fan, you likely have a failing fan with a bad bearing or poor commutator connection to the brushes. The fan is likely located above the passenger's feet area. It's held in by 3 screws and has a rubber tube that connects to the duct nearby that brings cool air back to the hub area of the motor. Sometimes there's a tight fit to wiggle the fan with blower in and out, but it's replaceable.

    OR you need to check the connectors for the fan power for burned contacts and distorted plastic housing from the heat from burned contacts. The burning changes the resistance which affects the current.

    Do you smell a burning hot plastic smell at any time?

    2014 Malibu 2LT, 2015 Cruze 2LT,

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