Question about 1997 Ford F150 Regular Cab

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Ac f 150 ford truck

When accelerating my ac swiches to the top defrost and when I pull my foot of the gas the ac starts blowing normal

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Hello santillani...the a/c duct routeing is controlled by a vaccum operated damper... the defrost, is the systems default mode. Sounds like you could have a vaccum line leaking or broken, or the linkage on the damper itself is not properly working. Also...on the later 90 model fords pickups, there is a 3-way vacuum valve behind the battery next to the firewall that i've found faulty, i would check that first, bout 8 buxs to replace it.
TIP: While you are under the hood, do a general inspection of all the rubber lines, hoses and belts, pcv valve and connector line. Your truck is 12 years old so a lot of rubber products may start to show deterioration.
Good luck...i hope this helps and will fixya up.

Posted on May 16, 2009


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