Skip the auto shop - Our mechanics make house calls

Q: When I turn my AC, my car shuts down.

asked by on

My AC works, it cools down the car, the problem is that: I notice when car is in "P" (But it does it in every shift) shift, with my AC on, I flood my car and it accelerate good but when I release the pedal the motor sounds like it will shut down with no power (when I have the AC off it doesn't happen) The AC compressor is a Universal one, and has a single relay outside the relay box, its holded near the fan, and a cable goes from the battery to the relay than to the button, than to the compressor, It wasn't me who made that, I bought the car like that. So today I was in a downhill and I turn the AC on and inmedietly the car shut down, it has happen to me like 5 times, only when the AC is on. I also noticed that tha car vibrate a lot more when the AC is on. The point is that when I turn the AC the car either shut down or the motor loses like "power" to the point that look like its going to shut down. The AC doesn't have any rare sound, it just make the car vibrate a lot. ERICK

My car has 166708 miles.
My car has an automatic transmission.

Hi Erick. It sounds like the idle is not being adjusted/compensated for the additional load of the ac compressor. Additional loads on the engine require the idle to increase to make sure the engine does not stall under the load. What sounds like is occurring is that there is no increase in idle to compensate for the load and is stalling the engine. I suggest having a qualified technician perform an inspection of the idle control system to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a rough idle inspection.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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

Q: What are your options when receiving a call on the hands-free system?

When a call comes in and you’re using the hands-free system, you have several different options depending on what you want to do. Here’s a quick introduction: Press the off-hook button to answer the call. Press the on-hook button...

Q: Windshield Wipers and Lights not working.

Hello, thank you for writing in. The wiper's motor circuit may have a short somewhere that is blowing the fuse. Weather can not only cause corrosion but can stress out the wiper motors and cause them damage as well. Both...

Q: Engine sputtering and manual gear-shifter is getting stiff.

Hi there. It's possible that the shifting issue could be related to the clutch, but that seems more like a gear linkage issue. The engine vibration is most likely not related; and could be caused by a damaged vacuum line...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...