# Car fan

**URL:** <https://community.cartalk.com/t/car-fan/72825>\
**Category:** Maintenance/Repairs\
**Created:** [June 3, 2012, 1:24am UTC](https://community.cartalk.com/t/car-fan/72825 "2012-06-03T01:24:22Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![mwkarrick](https://avatars.discourse-cdn.com/v4/letter/m/51bf81/32.png) [@mwkarrick](https://community.cartalk.com/u/mwkarrick)\
**Post date:** [June 3, 2012, 1:24am UTC](https://community.cartalk.com/t/car-fan/72825/1 "2012-06-03T01:24:22Z")

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have a 2001 saturn l200. When I have the car running for awhile, the temp gets half way and the fan comes on, but then shuts right back off and will not come on again. Recently I have replaced the radiator fan, the fan module, and the sensor. How does the car fan work? We have had to add a switch to the fan to turn it on when we have to. Can you help please.

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**Author:** ![missileman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/missileman/32/1366_2.png) [@missileman](https://community.cartalk.com/u/missileman)\
**Post date:** [June 3, 2012, 1:51am UTC](https://community.cartalk.com/t/car-fan/72825/2 "2012-06-03T01:51:19Z")

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How do you know that the fan should be on? Is the vehicle overheating? Using a switch to keep the fan on might cause problems with the engine running too cool.

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**Author:** ![RemcoW](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/remcow/32/2471_2.png) [@RemcoW](https://community.cartalk.com/u/RemcoW)\
**Post date:** [June 3, 2012, 5:15am UTC](https://community.cartalk.com/t/car-fan/72825/3 "2012-06-03T05:15:02Z")

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Not sure where the Saturn has this thing, but I’d see if your thermoswitch is working properly. It can be mounted anywhere in the coolant path. On some cars it is high up so will cause the engine’s fans to not turn on when the coolant is low - kinda a dumb design, imo. Anyway, you may want to find that switch on your car.

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**Author:** ![euryale1](https://avatars.discourse-cdn.com/v4/letter/e/41988e/32.png) [@euryale1](https://community.cartalk.com/u/euryale1)\
**Post date:** [June 3, 2012, 5:55am UTC](https://community.cartalk.com/t/car-fan/72825/4 "2012-06-03T05:55:56Z")

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Air in the engine coolant can expand and cause the sensor to be left high and dry. Has someone done a coolant flush on this car? Maybe it was not completely done. Also do you add coolant or does it stay at a normal level?