Q: My car A/C won't shut off, even when the car is off !

asked by on July 05, 2016

I live in a rural area down a dirt rocky road with lots of potholes. I drove up my driveway last night to check the mail and hit a huge pothole. When I came back down the driveway and parked my car and turned it off, taking the keys out of the ignition, my A/C was still blowing (and hard!) and wouldn't shut off! I even turned the knob to "off" and it still wouldn't shut off. My car was totally off and the keys were out of the ignition. Needless to say, my car battery is now completely dead after having no choice but to leave the car like that all night.

My car has 130000 miles.
My car has an automatic transmission.

You may have shorted out the A/C blower resistor that controls the blower speeds. This component is supplied power all the time and only the switch controls the motor speed. If the resistor terminals where the resistors are touched together then it can cause the blower to run with the key in the off position. Have a new blower resistor installed and charge or jump the battery. I’d recommend you get the car looked at by a qualified mechanic who can diagnose your A/C issue first hand. If a mobile mechanic can’t make it out to you I suggest jump starting it and driving it to your local mechanic. Good luck.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Car gets jerky when first accelerating

Although I would need a bit more information for a specific diagnosis, there are a few things that can make the vehicle feel jerky: Broken or worn engine and transmission mounts allow too much movement under the hood. While...

Can I Get Cold Air Without Running the Air Conditioner?

All vehicles produced today are equipped with air conditioning systems. If you do not want the air conditioning on but you would like fresh air to come into the vehicle then all you would have to do is turn the...

My check engine light is on even after replacing both O2 sensors.

When a car has as many miles as your has, the problems really start to stack up until it seems like everything happens at once. Reading and interpreting the codes can be more subtle than it appears.The guys at the...

Related articles

How to Use a Battery Charger
Most Most people who have been around cars for a good chunk of their lives have experienced the hassle and inconvenience associated with a dead battery. Sometimes it simply happens in the owner’s driveway, which is really the best case...
How a Car's Heating System Works
The The sun sets, and the air has a chill. You pause to flip your jacket collar up, and you walk briskly to your car door and slide into the driver's seat. Once you start your car, it’s only moments...
Can a Car Battery Freeze?
Cold temperatures can make it hard to start your car, and extreme cold can freeze a battery. Use a battery heater to make your car reliable in winter.