# A/C Vacume question

**URL:** <https://community.cartalk.com/t/a-c-vacume-question/17537>\
**Category:** Maintenance/Repairs\
**Created:** [August 1, 2008, 4:12pm UTC](https://community.cartalk.com/t/a-c-vacume-question/17537 "2008-08-01T16:12:52Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Ken\_Bucek](https://avatars.discourse-cdn.com/v4/letter/k/c57346/32.png) [@Ken\_Bucek](https://community.cartalk.com/u/Ken_Bucek)\
**Post date:** [August 1, 2008, 4:12pm UTC](https://community.cartalk.com/t/a-c-vacume-question/17537/1 "2008-08-01T16:12:52Z")

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I have a 2000 Ford Ranger 2.5L engine that I just replaced the A/C Compressor, Dryer, and venturi tube/filter, vacumed the system and recharged the system. It is working fine however the blend door is not operating properly and the cold air only comes out the defrost vents, I have narrowed the problem down to a vacume problem, this system uses vacume tubes to change the direction vents and open the blend door and there is zero vacume… My question is… how can I pinpoint where the vacume problem is?

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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:** [August 1, 2008, 4:21pm UTC](https://community.cartalk.com/t/a-c-vacume-question/17537/2 "2008-08-01T16:21:22Z")

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Check to make sure you didn’t unknowingly disconnect any vacuum hoses when you did this repair. The vent control has a vacuum line from the engine, thru a check valve, into vacuum reserve canister, and thru the firewall to the vent control panel.

Tester