Is this normal for '99 Ram 1500?

From : tush smells bush kills

Q: when i have the a/c or fan on and accelerate really fast the air will stop blowing out the front vents and instead blow out the vents under the windshield. as soon as i lift my foot off the gas it returns to blowing through the front vents. step on the gas again and itll go back to the windshield vents.... is this normal in this truck also i have size 225/75r-16 tires on my truck. would it be ok if i put 245/75r-16 instead or are they too wide for the current rims .

Replies:

From : tbone

no it indicates either a bad check valve or a minor vacuum leak. -- if at first you dont succeed youre not cut out for skydiving when i have the a/c or fan on and accelerate really fast the air will stop blowing out the front vents and instead blow out the vents under the windshield. as soon as i lift my foot off the gas it returns to blowing through the front vents. step on the gas again and itll go back to the windshield vents.... is this normal in this truck also i have size 225/75r-16 tires on my truck. would it be ok if i put 245/75r-16 instead or are they too wide for the current rims .

From : rm

mine has done that ever since the dealer worked on the ac 3 years ago. i have no idea where to even start looking for the leak. when i have the a/c or fan on and accelerate really fast the air will stop blowing out the front vents and instead blow out the vents under the windshield. as soon as i lift my foot off the gas it returns to blowing through the front vents. step on the gas again and itll go back to the windshield vents.... is this normal in this truck also i have size 225/75r-16 tires on my truck. would it be ok if i put 245/75r-16 instead or are they too wide for the current rims .

From : miles

tush smells bush kills!!!!!!!!!!! wrote when i have the a/c or fan on and accelerate really fast the air will stop blowing out the front vents and instead blow out the vents under the windshield. as soon as i lift my foot off the gas it returns to blowing through the front vents. step on the gas again and itll go back to the windshield vents.... is this normal in this truck also i have size 225/75r-16 tires on my truck. would it be ok if i put 245/75r-16 instead or are they too wide for the current rims most likely a vacuum leak. most common place for a leak is the small line that runs from the manifold underneath the air cleaner to the cruise control module thats under the battery. corrosion from the battery gets onto the line causing it to leak. does your cruise control operate normally on mine it would turn on indicated with the cruise light on the dash but would not maintain speed. after replacing the line the cruise now works and my a/c vents no longer flip when accelerating. .

From : rm

most likely a vacuum leak. most common place for a leak is the small line that runs from the manifold underneath the air cleaner to the cruise control module thats under the battery. corrosion from the battery gets onto the line causing it to leak. does your cruise control operate normally on mine it would turn on indicated with the cruise light on the dash but would not maintain speed. after replacing the line the cruise now works and my a/c vents no longer flip when accelerating. cruise works fine on mine. .