Ice and Rain Control Systems Which of the following are found in a laminated integral electrically heated windshield system? 1. Autotransformer. 2. Heat control relay. 3. Heat control toggle switch. 4. 24V DC power supply. 5. Indicating light. a. 1, 2, 4, 5. b. 2, 3, 4, 5. c. 1, 2, 3, 5.