Can't Control Heater & Defroster
courtesy of Bob, The Auto Answer Man
I have a 1996 jeep Grande Cherokee and my problem is when you accelerate hard and have the heater on it automatically switches to the defroster. After you let off the gas it then switches back. I hope you can help me and thanks for your time.
The direction of air flow on most cars is controlled via vacuum. Upon hard acceleration the engine's vacuum drops. This may be causing the car to go to default heater control (which is probably defrost). There may be a leak or a crack in a hose or a bad vacuum diaphragm that controls the air flow.
Bob, The Auto Answer Man
Have a car care question? Visit our automotive center and see if we've already answered it or a similar question.
More Tips & Tools to Help You
Live Better...For Less
- 4 costly car maintenance mistakes to avoid
- 5 common ways you are killing your car
- 7 secret sales tactics car salesmen hope you don't know
- 7 smart steps to switching your car insurance
- Your trickiest cleaning problems solved
- How to eliminate mosquitos for less Insider Report
- Choosing a roadside assistance plan
- Auto loan calculator
- Should you buy or lease you next car?
- Is a new car or used car best for your next purchase?
- Auto down payment calculator
- More helpful auto calculators