Aircon & more

The technical team at Valeo look at some common winter queries

Q: I have been told that maintaining a vehicle’s air conditioning system is just as important in the winter months as during the summer. Is this because in cold weather conditions the air doesn’t need to be cooled further?

A: Air conditioning (AC) systems don’t just remove heat from the air entering the vehicle, it also removes moisture from it. When there’s a lot of moisture in the air entering the vehicle it can make the conditions uncomfortable and can cause visibility issues – the windows steaming up, for example.
Also, during the autumn and winter months when the conditions are wetter (with snow and more rainfall), water is transferred into the cabin by occupants of the vehicle. When the interior heater is used, the water will evaporate and produce a humid atmosphere and cause the windows to steam up. By using the AC, these issues can be reduced or eliminated, which is why it is important to ensure the system is maintained during the winter months.

Q: When I have a customer vehicle in for a repair or service, I have heard I need to check the antifreeze quality of the engine coolant and, if necessary, change it, even during the summer months. Why does antifreeze need to be checked even during the summer when the coolant will not freeze?

A: Antifreeze is not just an additive to reduce the coolant freezing temperature, it also contains a lot of agents to ensure the engine cooling system is working at its best. Antifreeze contains corrosion inhibitors so components are not blocked or subject to reduced efficiency. This has a big impact compared to when only water is used.
Antifreeze also contains agents to provide better transfer of heat from the engine to the radiator, reducing the possibility of an engine overheating.
These agents degrade over time so should be checked at every service to ensure the vehicle is running as efficiently as possible and to reduce the possibility of engine damage.

Q: Why do batteries and alternators fail more often during the winter months?

A: During winter months a vehicle’s electrical system is under higher load due to more functions being used. The minimum number of functions usually used on a day-to-day basis includes the fan blower motor, rear screen heater, wiper motor, radio and lights and the load can vary depending on the type of vehicle – some use more power than others.
Once the power consumption of all these functions is added together, there will be a lot of demand from the vehicle’s charging system – the alternator and battery. If the alternator or battery is no longer operating at its most efficient, the extra demand will cause the battery to no longer hold enough charge when needed, meaning it will be insufficient to start a vehicle.
During the lighter and warmer months, the electrical demand is a lot less so a battery or alternator that is not at its most efficient will still be able to supply enough charge and the issue will go unnoticed.