# High Speed on Heat/AC Fan

**URL:** <https://community.cartalk.com/t/high-speed-on-heat-ac-fan/42>\
**Category:** Maintenance/Repairs\
**Created:** [May 16, 2007, 4:47pm UTC](https://community.cartalk.com/t/high-speed-on-heat-ac-fan/42 "2007-05-16T16:47:56Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![joepepsi](https://avatars.discourse-cdn.com/v4/letter/j/b38774/32.png) [@joepepsi](https://community.cartalk.com/u/joepepsi)\
**Post date:** [May 16, 2007, 4:47pm UTC](https://community.cartalk.com/t/high-speed-on-heat-ac-fan/42/1 "2007-05-16T16:47:56Z")

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Hello, Position 5 (high) on the 2001 Chevy Venture’s heat and A/C fan no longer works. Is this a relay or fuse that can be easily replaced? Do I have to get it from the dealer?  
  
  
  
 Thanks in advance!

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**Author:** ![myronwms](https://avatars.discourse-cdn.com/v4/letter/m/4da419/32.png) [@myronwms](https://community.cartalk.com/u/myronwms)\
**Post date:** [May 16, 2007, 7:27pm UTC](https://community.cartalk.com/t/high-speed-on-heat-ac-fan/42/2 "2007-05-16T19:27:44Z")

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Looking at the schematics for your Venture it shows a “Blower motor relay” as part of the “Blower Motor Resistor Assembly”. Power is supplied from a 30A circuit breaker at contact G. Verify that you have 12 volts there. If so the breaker is probably OK. Your next stop would be a GM parts dept. (Or maybe a boneyard.)

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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:** [May 17, 2007, 1:29am UTC](https://community.cartalk.com/t/high-speed-on-heat-ac-fan/42/3 "2007-05-17T01:29:50Z")

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How the fan speeds work in your vehicle is, on all speeds other than high, the voltage passes through a resistor block. When the fan is switched to the high position, the fan motor recieves full battery voltage.

On some vehicles there’s a component called a high speed fan relay. What this does is it switches between the lower speeds and the high speed. If your vehicle has a high speed fan relay, this would be the first component to suspect.

[b]Tester