GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC C-Series Medium Duty Truck B7 🢒 Engine 🢒 Engine Controls - 7.4L 🢒 Engine Controls Component Views
Figure 1:

Engine Harness Components, Upper Right Rear
Object Number: 220287 Size: MF
(1)Ether Injector Control Valve
(2)Air Intake Heater Relay C1 (ring terminal)
(3)Air Intake Heater Relay
(4)Air Intake Heater Relay C2 (2 cavities)
(5)Ether Injector Sensor
Figure 2:

Engine Harness, Left Front (LG5)
Object Number: 235946 Size: LF
(1)Engine Speed Governor Control Module
(2)Air Intake Heater Engine Coolant Temperature (ECT) Switch
(3)Engine Coolant Temperature (ECT) Gauge Sensor
Figure 3:

IP Harness to Dash Panel, Center Forward View
Object Number: 239914 Size: LF
(1)Accelerator Pedal
Figure 4:

Engine Harness, Upper Right Front View (LG5)
Object Number: 239936 Size: LF
(1)Engine Coolant Temperature (ECT) Switch
Figure 5:

Engine Harness to Engine Upper Right Forward View (LG5)
Object Number: 231579 Size: LF
(1)Engine Harness
(2)Engine Coolant Temperature (ECT) Switch
(3)Automatic Engine Shutdown Engine Coolant Temperature (ECT) Switch
(4)A/C Compressor Clutch
(5)Air Intake Heater Relay
Figure 6:

Engine Coolant Temperature (ECT) Sensor and Switches Upper Right Side View (LG5)
Object Number: 231583 Size: LF
(1)Engine Coolant Temperature (ECT) Switch
(2)Automatic Engine Shutdown Engine Coolant Temperature (ECT) Switch
(3)Engine Coolant Temperature (ECT) Gage Sensor