# Kia's fan doesn't work unless I hit a bump

**URL:** <https://community.cartalk.com/t/kias-fan-doesnt-work-unless-i-hit-a-bump/1548>\
**Category:** Maintenance/Repairs\
**Tags:** sephia, heating, airconditioning, kia, fans\
**Created:** [July 10, 2007, 9:08pm UTC](https://community.cartalk.com/t/kias-fan-doesnt-work-unless-i-hit-a-bump/1548 "2007-07-10T21:08:27Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![wanpi17](https://avatars.discourse-cdn.com/v4/letter/w/eb8c5e/32.png) [@wanpi17](https://community.cartalk.com/u/wanpi17)\
**Post date:** [July 10, 2007, 9:08pm UTC](https://community.cartalk.com/t/kias-fan-doesnt-work-unless-i-hit-a-bump/1548/1 "2007-07-10T21:08:27Z")

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I’ve got a problem with my 98 Kia Sephia. The fan for the AC/Heater won’t work unless I hit a bump while driving. Once it comes on it will stay on as long as I keep the car running, but if I turn it off, the fan usually will not work again until I hit a bump. The problem seems to not be as severe on really hot days.  
  
  
  
 Any suggestions

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [July 10, 2007, 9:41pm UTC](https://community.cartalk.com/t/kias-fan-doesnt-work-unless-i-hit-a-bump/1548/2 "2007-07-10T21:41:30Z")

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The fan motor is driven through the contacts of a relay energized when the fan switch is turned to one of the positions. This sounds like contact corrosion.

The location of the relay should be shown in a repair manual from the parts store, or the local dealership can tell you where it is.

-mountainbike

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [July 10, 2007, 9:55pm UTC](https://community.cartalk.com/t/kias-fan-doesnt-work-unless-i-hit-a-bump/1548/3 "2007-07-10T21:55:41Z")

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[b]The next time the fan fails to run, while at a stop, reach over to the passenger side of the dash, and give the top of the dash a sharp blow with the side of you fist. If the fan starts working, replace the fan motor.

Tester[/b]

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**Author:** ![star882](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/star882/32/39_2.png) [@star882](https://community.cartalk.com/u/star882)\
**Post date:** [July 10, 2007, 11:25pm UTC](https://community.cartalk.com/t/kias-fan-doesnt-work-unless-i-hit-a-bump/1548/4 "2007-07-10T23:25:25Z")

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Probably a loose connection somewhere.  
Is the thermostat digital (with buttons and a LCD) or analog (with a dial)? If it’s digital, how many speeds are there? Do you hear any clicking when the speed is changed?  
If the thermostat is digital with much more than 3 or 4 speeds and does not click when the speed is changed, the motor is electronically commutated, which means it uses transistors instead of relays for control.