Skip the auto shop - Our mechanics make house calls

Q: AC not working.

asked by on

The AC is not working. The fan does not blow cold air.

A: An A/C system can be divided into 3 differe...

An A/C system can be divided into 3 different sub systems. These sub systems work for the most part independent from each other. The heater part of it works off of water from your engine. The refrigerant part is what makes the air cold, it is a sealed system that works similar to you home refrigerator. The last sub system is the duct and fan. This is what directs the air to the vent/floor/defroster, and actually blows the air. If the refrigerant system is low, a pressure sensor will detect this and not allow the system to come on. A technician will have the proper equipment to recharge your system and find the leak. Usually electronic leak detection equipment or ultraviolet dyes are used for this. Another common issue is actuator failure. Actuators are part of the duct system. They direct air from to the proper areas for cooling or heating. If the door that directs the hot/cold air is stuck half way or on the hot side because of actuator failure, it will blow warm/hot even if the refrigerant side is doing its job. Actuators can be difficult to get to as they are behind the dashboard usually. There are also several of them so seeking help from a technician is advised.

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・Save up to 30%

Get a quote

What others are asking

Q: Remove reinstall heater core

Hello there, thank you for asking about your 1990 Geo Storm. Your best option would be to purchase a service manual for your year model. The entire instrument panel must be removed in the process as well as many other...

Q: Brake lights are not bright, drivers can barely tell I am braking

Hi. There are 2 likely possibilities for your poor lighting. The first is a bad ground connection, limiting the power that can electrically flow through the light bulbs. The second possibility is that the wrong bulbs have been inserted in...

Q: I have oil leaking from my car I had a estimate done on it last week and told me to replace the whole crankshaft.

Hi there. With a car of this age, it should be highly unlikely that the car would need the crankshaft replaced as this is typically something that does not fail unless under catastrophic conditions. There are a number of places...

Related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...