Elantra L4-1595cc 1.6L DOHC (1993)
Air Conditioning Switch: Description and Operation
Air Conditioner Relay
OPERATION
When the driver turns on the A/C system, a positive voltage signal is supplied to the ECU (as an indication that the A/C system is needed) and to one
side of the A/C relay coil.
The ECU determines if engine conditions are suitable for A/C operation (idle speed, ignition timing and air/fuel mixture). If the ECU senses that
conditions are suitable for A/C operation, it supplies the ground circuit for the A/C relay coil, energizing it. This allows the relay to supply voltage to the
compressor clutch.