The Unusual Object on Your Vehicle’s Dashboard? The device is a sunload sensor. The purpose of this is for

Contemporary automobiles are replete with remarkably clever engineering, much of which often goes unnoticed. Consider, for example, the small chips on your car’s windshield. These chips are found on almost every vehicle, but unless someone specifically draws your attention to them, they are practically invisible to us due to our lack of attention.

Equally, if not more nuanced, is the solar, or sunload, sensor. Typically, it appears as a small, circular protrusion located at the rear of your dashboard. However, its shape and position may vary. Regardless, rest assured that it is present, even if you have never observed it before.

According to Auto Service World, a Canadian automotive aftermarket industry magazine, sunload sensors are typically positioned at the upper part of the dashboard and are commonly installed on a detachable plate, speaker grill, or defroster vent. “There is typically one on each side of the dash to account for variations in sunlight exposure.”

However, what is their purpose? Predictably, the purpose is to monitor the amount of sunlight penetrating the interior of the vehicle. However, the reason behind this may be somewhat surprising. The purpose of this sensor is not to monitor the brightness level outside, as one might assume, in order to enable features such as automatic headlights or adjust the brightness of the dashboard display during the night. Although there is a separate sensor for that specific function, it is not the one being referred to here.

Instead, the sunload sensor is a component of the climate control system.

According to Auto Service World, sunload sensors are used to measure the strength of sunlight and make adjustments to the HVAC control system in order to enhance the comfort of the driver and passengers during sunny days.

The fan speed may increase, and the blend doors may open to enhance cooling in bright sunlight conditions.

In essence, these sensors operate by utilizing a photodiode, which is a semiconductor diode that converts photon radiation, such as visible light, but also has the capability to detect infrared, X-rays, gamma rays, and other forms of radiation, into an electric current. Nevertheless, with the escalation of light intensity, the resistance of the diode also rises, leading to a decrease in the number of volts transmitted from the sensor to the car’s internal monitoring systems.

Functioning smoothly and efficiently, the control module interprets the decrease in voltage as a cue to enhance the performance of the A/C systems, preventing the driver from suffering the dreadful consequence of overheating inside an SUV.

And as anyone who has experienced being trapped in a car with a malfunctioning HVAC system can attest, this statement is not entirely exaggerated. The sunload sensor plays a crucial role in managing the interior heat load of a vehicle by detecting and measuring the amount of sunlight entering the vehicle. According to Auto Service World, sunlight can contribute up to 60 percent of the total interior heat load that the vehicle’s system needs to counteract.

Could you please clarify or rephrase your statement? Without this small protrusion on your dashboard, your car could potentially absorb up to two and a half times more heat compared to when it is present. Whew!