# A/C stays on **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** nissan, frontier\ **Created:** [October 20, 2009, 8:06pm UTC](https://community.cartalk.com/t/a-c-stays-on/38382 "2009-10-20T20:06:20Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![fredkinder](https://avatars.discourse-cdn.com/v4/letter/f/6de8d8/32.png) [@fredkinder](https://community.cartalk.com/u/fredkinder)\ **Post date:** [October 20, 2009, 8:06pm UTC](https://community.cartalk.com/t/a-c-stays-on/38382/1 "2009-10-20T20:06:20Z")
2009 Nissan Frontier. When the air flow knob is turned to windshield defrost and then turned back to regular air flow, the A/C stays on until the ignition is turned off. My service man at Nissan says this is normal. I don’t believe it. ---
**Author:** ![Beadsandbeads](https://avatars.discourse-cdn.com/v4/letter/b/c57346/32.png) [@Beadsandbeads](https://community.cartalk.com/u/Beadsandbeads)\ **Post date:** [October 21, 2009, 12:00am UTC](https://community.cartalk.com/t/a-c-stays-on/38382/2 "2009-10-21T00:00:14Z")
How do you know the AC stays on? ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [October 21, 2009, 3:41pm UTC](https://community.cartalk.com/t/a-c-stays-on/38382/3 "2009-10-21T15:41:00Z")
Surely the a/c compressor stops cycling if you turn the blower control to ‘off’. Or is it some cutting edge climate control system you can’t fully shut off? Go to the dealer and check out another Frontier. See if it’s just yours. ---
**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\ **Post date:** [October 21, 2009, 9:53pm UTC](https://community.cartalk.com/t/a-c-stays-on/38382/4 "2009-10-21T21:53:40Z")
If the car has a failure why would the Dealer not fix it and submit a claim? Have you expressed your doubt to the service manager? ---
**Author:** ![endorf](https://avatars.discourse-cdn.com/v4/letter/e/85e7bf/32.png) [@endorf](https://community.cartalk.com/u/endorf)\ **Post date:** [January 30, 2010, 5:55pm UTC](https://community.cartalk.com/t/a-c-stays-on/38382/5 "2010-01-30T17:55:49Z")
This is a feature built in to this vehicle to " keep moisture from accumulating, which could cause mold to grow " is what I was told. There is a way to disable this. You may want to check all the car forums out there. I remember seeing something about a switch up under the dashboard that you can reset. I wish I could help you more. ---
**Author:** ![EllyEllis](https://avatars.discourse-cdn.com/v4/letter/e/f14d63/32.png) [@EllyEllis](https://community.cartalk.com/u/EllyEllis)\ **Post date:** [January 30, 2010, 6:55pm UTC](https://community.cartalk.com/t/a-c-stays-on/38382/6 "2010-01-30T18:55:31Z")
It is normal for the A/C to work on “defrost” but I think it should shut off when you go to heat or vent. ---
**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\ **Post date:** [January 30, 2010, 7:15pm UTC](https://community.cartalk.com/t/a-c-stays-on/38382/7 "2010-01-30T19:15:50Z")
I believe Endorf may be right that some of the new systems do this. It prevents the musty smells by allowing the evaporator core to dry some, thus not becoming a good environment for spores. I’ve heard of this before too.