Car Questions
RepairPal is your advocate for car care advice and guidance

A/C goes off

(1999 Chevrolet Monte Carlo)
in Tucson, AZ on August 25, 2010
As i accelerate at about 30 MPH the A/C stops blowing out of the dash vents & some blows out from under the dash.
Displaying 1 answers & 1 comments
Popular Answer
of FiveStar ServiCenter on August 25, 2010
Your HVAC (heating, ventilating, air-conditioning) system air distribution is driven by engine vacuum. The fail mode (in the event of loss of vacuum) directs air to defrost and some to floor.

Engine vacuum decreases on acceleration due to throttle opening. Because of this there is a vacuum reserve canister, I believe it's a plastic ball mounted on the firewall. Check to see If that is disconnected or cracked, otherwise there is a check valve inline which may have failed.

Best of luck
on August 25, 2010
Thanks very much. I'll check it out tonight.
Get a repair estimate
RepairPal estimates are guaranteed at over 2,000 quality certified locations nationwide.
Or interested in getting a repair? Find a Shop

Similar Questions

View answers to similar questions from RepairPal's community of auto experts and enthusiasts.
what would cause the no 1 fan relay to stick in...
I have replaced this no 1 relay 7 times and and usually fixes it temporarily the other 2 relays 3 times ea. when the ...
Where is the radiator switch on the radiator lo...
I have an 04 hyundai xg350 i replaced the temperature sending sensor that goes into the thermostat housing, new therm...
Didn't find what you were looking for?