AC Only Works When Driving: Causes & The Solutions

The air conditioning is a wonderful thing. If you have it and it’s working, there is nothing to do but enjoy the frigid air. However, when your car doesn’t have AC or only works when driving, that can be a serious problem. It might seem like something you could ignore at first, but if you wait to get this taken care of soon, it could cause other problems with your vehicle in the future. Here are some causes of AC only working while driving and how to fix them:

Blocked Radiator Hose

If you’re noticing that your A/C only works while driving, it could be caused by a blocked radiator hose. The radiator is the device that cools down the engine and is where the coolant circulates through to keep your car running at a comfortable temperature. If there’s dirt or other particles in this area, they can clog up the tubes and prevent proper coolant circulation throughout your vehicle. This will cause your air conditioner to struggle as well as other functions of your car such as turning on headlights and windshield wipers.

To fix this problem, remove the fan shroud (it’s easy on most cars) and check for any obstructions in front of or behind the fan blade(s). Remove anything blocking airflow there and then test again. If this doesn’t work or you see no obstructions, check both incoming hoses (that attach between your engine block and radiator) for a clog such as leaves, insects etc., which can get lodged inside them over time; remove them if found with pliers then reassemble everything back together again before testing again.

Incorrect Refrigerant Amount

The A/C system uses refrigerant and a compressor to cool down the air. The system works by passing the refrigerant through an evaporator coil that extracts heat from the air, turning it into a gas. Then, this hot gas is sent back to a condenser coil where it’s cooled down and changes back into liquid form. Once returned to its liquid state, it can be reused in the loop again and again until all of its heat has been extracted from the air.

To keep this process running smoothly, there needs to be just the right amount of refrigerant in your car’s A/C system. If there’s too little or too much in there (or if you’re using an incorrect type), your A/C won’t work as well as it should—and you’ll see symptoms like those listed above!

Compressor Failure

Compressor failure is one of the most common reasons for A/C only working when driving. When a car’s cooling system overheats, it can break down and fail over time. This can be caused by running too many accessories or by having an improper liquid mix ratio in your radiator. The best way to prevent premature compressor failure is to make sure that your engine always has sufficient coolant levels and that you’re running only a few accessories with it (like running extra lights or blowers on top of A/C). If these are not possible solutions for you, there may be other underlying problems causing your compressor to overwork itself before its time—such as faulty belts.

Compressor Belt Issues

The compressor belt is a rubber belt that connects the compressor and the pulley. It’s responsible for turning on your A/C, which means it’s important to ensure it’s in good condition. If this belt breaks or becomes loose, your air conditioning compressor won’t work properly—and since air conditioning is only available while driving, you’ll be stuck with no cool air when parked.

This is why many people have trouble with their A/C working only when they’re driving: they believe their problem lies within the refrigerant lines or inside of their vehicle itself. However, if you’ve checked those areas without any luck and still feel like something simply isn’t right, it’s likely that there are issues with either your evaporator core (the part of your system that cools down) or another part connected to either side of it (such as a wiring harness).