Question about 1999 Ford F150 Regular Cab

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Vent blower when you go up a incline or get on the gas hard vent blower switches to defrost. I think it is a vacume problem?

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  • rjgunz Sep 29, 2008

    thankyou, but i allready replace the valveand hoses.any ideas?

  • rjgunz Sep 29, 2008

    thankyou, i allready replace the valve and hoses. do you have an other solution?

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Hello.Yes,it is a vacume problem.What happens is that the vacume controled a/c control head looses engine vacume because the one-way vacume valve fails.This valve is located near the firewall.Follow the vacume tube coming out of the evaporator housing in the engine compartment.

Posted on Sep 29, 2008

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