There’s nothing more frustrating than weak air flow on a hot summer’s day! Unfortunately, there’s no easy diagnosis here; insufficient air flow could stem from a number of possible problems. For example, it might be an instance of mold or mildew building up in the evaporator core. It could also be a loose hose, a bad ventilation fan, or blown seals. A qualified mechanic can isolate the root of your A/C problems.
Warm air coming from your A/C is never a good sign. There could be a number of potential factors here, such as a clogged expansion valve; a faulty compressor clutch; a blown fuse; or even leaks within the A/C. The only way to know for sure what’s causing that warm air is to take your car to a qualified inspection for an appraisal.
A leak in your A/C is bad news, without question—but what causes it? The short answer: age and moisture. Over time, the rubber hoses and seals in your A/C lose elasticity and allow Freon to escape, all while allowing moisture to enter. When moisture mixes with your A/C’s refrigerant, it creates a corrosive acid, which destroys your A/C from the inside out. This is definitely something to have analyzed and repaired by a trained mechanic.
If you think your A/C has a leak, there are a couple of methods you can choose to help detect leaks. One option is to use black light-enabled dyes; many refrigerants are mixed with UV dyes, which allow them to show up under a black light. There’s also the “sniffer,” a special device that can zero in on the refrigerant’s chemical compounds and detect possible leaks. Ask your service technician about these options!
Nobody likes an A/C that emanates bad smells! There are a couple of possible causes of A/C odors, the first being dirty, old air in the cabin filter. The second is an evaporator case that’s developed mold, which could point to more systematic problems with your unit.