Relay 1 Inoperative

Relay not connected. Open in relay coil. Open in circuit between controller and relay or poor connection. Open in relay grounding circuit. Defective controller. Circuit between signal feed wire of sensing resistor and controller open or poorly connected. Sensing resistor terminals disconnected. Relay main terminal disconnected or defective. Quick preheat terminals disconnected, poorly connected, or open in wiring. Grounding terminal of engine harness disconnected.