Blower fan does not function

Tiny
VINCENTJC
  • MEMBER
  • 2003 OLDSMOBILE BRAVADA
  • 6 CYL
  • AWD
  • AUTOMATIC
  • 92,000 MILES
2003 Oldsmobile SUV


1. Blower fan does not turn on for either heater or A/C. It does usually operate at a very low fan speed level. It however cannot be controlled, or either turned on or off. When the car is shut off the fan will not shut off and eventually the battery will go dead. The battery has to be disconnected each evening.

2. The higher speed fan and fan adjustment may occasionally come on when the car is started but there is no switch control and turn on is at random and not at the will of the operator. After the car is shut down, the fan may go off and come back on it own at the next start up but this happens at random times. If the higher speed fan does come on, it will function constantly and its speed cannot be adjusted.

3. When the car is shut off the high-speed fan will not shut off and eventually the battery will go dead. The battery has to be disconnected each evening.

4. The fan speed adjustment does not function at all.

5. The on-off switch does not function.

6. The ambient temperature sensor never reads above 50 degrees even though the temperature outside may be 90 degrees.

7. In cold weather the outside temperature reading appears to function, however, its accuracy is unknown as the outside temperature reading sometimes cycles randomly but always below 50 degrees.

8. It may not be related but at the time the problem surfaced, the left side seat bottom heater stopped functioning.

9. The blower motor and the control unit have been replaced but the problem persists.

10. What are the possible causes?
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Sunday, December 26th, 2010 AT 4:36 PM

7 Replies

Tiny
MERLIN2021
  • EXPERT
Scan it for codes, but this GM system is tied into your ignition switch, and if the controller was tested? And replaced, the igntion switch could be the problem, especially since it wont shut off!
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Sunday, December 26th, 2010 AT 4:44 PM
Tiny
VINCENTJC
  • MEMBER
Thank you.

As far as I know the ignition switch was not tested. The heater- A/C on/off switch turns the controller on and off, or that is what the display indicates, but the fan remains on when and if it comes on. However, the fan speed control does not work at all although the indicator lights adjust as though the fan was working. Is that function also controlled by the ignition?

Does the ignition swithch also control the outside temperature sensor readings?

Your suggestion implies that the ignition switch overrides the controller swithc?

Thanks again.

Vince
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Sunday, December 26th, 2010 AT 5:04 PM
Tiny
VINCENTJC
  • MEMBER
Also there are no codes showing.
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Sunday, December 26th, 2010 AT 5:04 PM
Tiny
MERLIN2021
  • EXPERT
What I can tell you is this can be put on a scanner and all these parts tesed for performance, switch position accuracy, and faults! This is the way of the modern automtive world, without scanning, we are best guessing. If a switch is shorted, anything goes. Your ambient sensor probably needs replacement due to it's inaccurate readings. It's usually mounted at the radiator support. Power to the controller is supplied thru the ignition switch, but the fault can be wiring or the fan switch. But when the ignition is in the off position, even a bad switch should have the power to it killed! I recommend goeing for the extra cost of a scan.
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Sunday, December 26th, 2010 AT 5:17 PM
Tiny
VINCENTJC
  • MEMBER
Thank you, I will get a scan. I appreciate your consideration.

Vince
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Sunday, December 26th, 2010 AT 5:26 PM
Tiny
MERLIN2021
  • EXPERT
Let me know, I'll be here.
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Sunday, December 26th, 2010 AT 6:18 PM
Tiny
VINCENTJC
  • MEMBER
I will. Thanks again.

Vince
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Sunday, December 26th, 2010 AT 6:33 PM

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