I have a 2010 Silverado Every time I turn on my truck with the ac running my low speed radiator fan will kick in for about 10 seconds and then swap to the high speed fan and stays on almost continuously. Pretty annoying. This happens even if the the truck has been sitting overnight and is cold on its first start up.

After engine comes up to temp it sits just over half on the gauge.

I have also tried to fill the ac with refrigerant recently because the truck doesn’t get that cool. After filling there was no change.

Have tried swapping low and high speed fan relays no change and the coolant is topped off. Any ideas ?

  • 1
    Welcome to Motor Vehicle Maintenance & Repair! Try it without the AC on. The fan will run as long as the AC compressor is running. It's designed that way so the AC will function no matter what speed the vehicle is going. Sep 13, 2020 at 17:21
  • But is it suppose to be the high speed ? Rather than the low speed ? It’s super loud . Sep 13, 2020 at 18:39
  • Maybe it's the fan that's the problem @EricLievanos. Excess fan noise could be a sign it's got bad bearings.
    – GdD
    Sep 13, 2020 at 19:34
  • Yes, I believe it should be the high speed fan. Again, I believe it is behaving as it should be behaving. Sep 13, 2020 at 22:49
  • Notoriously loud. What changed? Sep 14, 2020 at 19:20


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