what's wrong with my a/c

RJ Way

Asked by Jul 20, 2014 at 11:25 PM about the 1999 Ford F-150 Work SB

Question type: Maintenance & Repair

A/c works fine until I hit a curve or take a turn, then I hear a vent or door
"thump" close under the dash. I can turn it to OFF 3 or 4 seconds then turn
back to max a/c and it blows cold again until I take another curve or turn...
Any ideas?

4 Answers


Could be the check valve to the heater/A.C. door under the dashboard is weak or the vacuum line to it is leaking.

3 out of 3 people think this is helpful.
RJ Way

Thanx BoholMark, I'll check it out

Yea the vacuum under the hood.

1 out of 1 people think this is helpful.

Oh good. Was it lose or just old and dried out?

1 out of 1 people think this is helpful.

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