Blower Speed Compensation
WARNING: This page is about a different car, the 2003 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.
Sunload
When the in-vehicle temperature and the sat temperature are try close, the blower will be operation at low speed. The low speed will vary depending on the sunload. During conditions of high sunload, the blower low speed in "normal" low speed (approx. 6V). During low or no sunload conditions, the low speed will drop to "low" low speed (approx. 5V).