AC–58 AIR CONDITIONING SYSTEM – TROUBLESHOOTING Heater Relay Circuit CIRCUIT DESCRIPTION The heater relay is switched on by signals from the A/C amplifier and switches power to the blower motor. WIRING DIAGRAM B From HTR Fuse A/C Amplifier R-L 2 2 2 HTR 4 1 5 ALT 2 3 L-W 3 L-W 5 L-W 16 2 IB2 IF1 A14 HR L-R Blower Motor 2 Control Relay 1 2A 2 B W-B Battery EB N13036