FRONT A/C FAN BLOWING LOW EVEN WHEN KNOB IS IN OFF POSITION

  • Tiny
  • vstowe
  • 2003 Pontiac Montana
  • 15,000 miles

The A/C fan will only blow on low, if you turn the fan switch it does not work at all. To get it to work it's in the 'off' position, but there it will blow a very minimal amount of air. Back A/C works great! It started suddenly when we hit a bump, at first it would just take a few tries to get the fan back working. But as time has went by, it is down to this - low (sometimes it seems less than low) air flowing from front vents and if we turn the fan knob (low/med/high) it will stop working all together. Please give some help on what this could be. I've looked online and thought it could be the blower motor resistor block, but my husband seems to think it's the fan switch on the dash. How do we check to see which it is?

Tuesday, July 24th, 2012 AT 6:15 PM

9 Answers

  • Tiny
  • saturntech9
  • Expert
  • 28,864 posts

The resistor wont cause the fan to work with the switch off. Do you have a mulitmeter to do some testing?Also do you have manual ac or auto climate control?

Was this
answer
helpful?
Yes
No
Tuesday, July 24th, 2012 AT 6:20 PM
  • Tiny
  • saturntech9
  • Expert
  • 28,864 posts

Usually the way the switches work is they supply a ground to different parts of the resistor to make the different speeds.

Was this
answer
helpful?
Yes
No
Tuesday, July 24th, 2012 AT 6:22 PM
  • Tiny
  • vstowe
  • Member

I do not have a multimeter. It's a manual climate control. The knob on the dash for the fan can be turned, it blows very little air in the off position as well as between med/high position, sometimes this changes and instead of these positions it may be the high only position with very little air coming out. How do I go about checking to see if it's the switch on the fan knob or the resistor? Everyone keeps telling me it's the resistor due to the fact that only one speed is working on the unit.

Was this
answer
helpful?
Yes
No
Tuesday, July 24th, 2012 AT 8:33 PM
  • Tiny
  • saturntech9
  • Expert
  • 28,864 posts

Do you have factory video entertainment?Also you will need a multimeter to check this out to figure out whats going on.

Was this
answer
helpful?
Yes
No
Wednesday, July 25th, 2012 AT 1:23 AM
  • Tiny
  • vstowe
  • Member

There's no video entertainment on the van. The a/c controls are located right below the radio/cd player. Can I buy a multimeter at a auto parts store? And what am I checking with it?

Was this
answer
helpful?
Yes
No
Thursday, July 26th, 2012 AT 5:01 PM
  • Tiny
  • vstowe
  • Member

Here's what it looks like

Was this
answer
helpful?
Yes
No
Thursday, July 26th, 2012 AT 5:02 PM
  • Tiny
  • saturntech9
  • Expert
  • 28,864 posts

Yes you can buy a multimeter at the auto parts store. You would be checking the blower motor circuit with it. Can you feel this little bit of air coming thru the vents with the blower off without the van moving?

Was this
answer
helpful?
Yes
No
Thursday, July 26th, 2012 AT 5:17 PM
  • Tiny
  • vstowe
  • Member

The knob is in the off position to get any air to blow out, sometimes it'll work if I move the knob, but most of the time if I move it from this position no air will blow. Doesn't matter if the van is sitting still or moving as long as I don't touch the knob it'll blow and blows cold!

Was this
answer
helpful?
Yes
No
Thursday, July 26th, 2012 AT 5:44 PM
  • Tiny
  • saturntech9
  • Expert
  • 28,864 posts

I was only asking because if it only had air coming thru the vents with the switch off and moving that would just be fresh air being brought in so you didnt fall asleep at the wheel. So do you have a multimeter yet so we can do some testing?

Was this
answer
helpful?
Yes
No
Thursday, July 26th, 2012 AT 6:38 PM

Please login or register to post a reply.

Similar Questions