Where is the starter relay located in the Audi A4L?
1 Answers
The starter relay position in the Audi A4 is on the left side of the drainage trough, next to the engine control unit. Working principle of the relay: The coil of the starter relay is connected in series with the operating winding of the compressor motor. During motor startup and operation, the operating current passes through the relay coil, while the control contacts are connected in series with the startup winding, controlling its opening and closing. The relay's control contacts are normally open. When power is initially applied, only the relay coil and operating winding carry current. Since the rotor is stationary, the startup current is very high, causing the relay coil to attract the armature upward, closing the moving and stationary contacts to engage the startup winding, allowing the compressor to begin rotating. As the speed increases, the current decreases, and the armature falls back by its own weight, opening the contacts to complete the startup process. Function of the starter relay: It assists the motor in starting and automatically disconnects the auxiliary winding after startup to prevent burning out the auxiliary winding coil. When the motor's operating winding is energized and transitions to normal operation, the starter relay cuts off the power to the startup winding.
