Car air conditioning
If you're interested in buying a used car, you may have seen advertisements stating that the car's air conditioning needs a charge. This terminology can be confusing, so we decided to explain exactly what to expect when you see (or hear) this phrase.
Needs a Charge
When sellers say that an air conditioning system needs a charge, what they mean is that the air conditioning is out of refrigerant fluid. Most likely, this means the system has a leak. The fluid in an air conditioning system simply does not get used up like gasoline. A home refrigerator works much like an air conditioning system. How often you need to "charge it up?" Probably never.
What Does It Really Need?
Unfortunately, the simple explanation that the air conditioning "needs a charge" rarely tells the whole story. For one thing, air conditioning systems are supposed to be closed; they aren't designed to lose any fluid, and they shouldn't need replenishing. With that said, it's possible for air conditioning systems to lose some fluid over time, but even that likely means a small leak in the system. So it is possible that "charging it up" will help the air conditioner blow cold air, but if the leak isn't properly fixed, you're running on borrowed time. We've seen A/C systems get a fresh shot of fluid and work well for several months, but there's really no way to be sure unless you take the car to a qualified air conditioning repair shop.
More likely, however, the car's air conditioning system needs more than just some fluid. After all, if fixing the air conditioning were as easy as adding fluid, wouldn't the seller do that before listing the car for sale?
How Can You Know for Sure?
Unfortunately, it isn't always easy to find out exactly what a car needs to get its air conditioning system working again. Pouring additional fluid into a leaky system will cause the air conditioning to operate temporarily, until it drains out again from the leak.
As a result, the only way to know with certainty what a car needs when it comes to air conditioning is to take it to a trusted mechanic, who can inspect the entire system for leaks or faults. We suggest a mechanical inspection anyway when you're buying a used car. If air conditioning is important to you, a potentially faulty system is all the more reason to make sure to get an inspection before signing the papers.
The implication of "just needs a charge" is that the problem is a simple one with a very inexpensive fix. The truth is that it's a lot more complicated than that. If you're looking at a car from the 1990s, the system may have to be converted to a new kind of refrigerant that's better for the environment. Even if you're looking at a newer car, a qualified shop will have to find and repair the leak, which could get expensive. If you really want that specific car, ask a local shop for their hourly repair rate and then factor that into the price of the car you want to buy.