C 3500 HD Truck 2WD V8-6.5L DSL Turbo VIN F (2001)
Glow Plug Relay: Description and Operation
GLOW PLUG RELAY
The glow plug relay is mounted at the rear of the left cylinder head. The glow plug relay is a solid state device which operates the glow plugs.
The PCM uses a ignition voltage signal to control the solid state circuitry of the glow plug relay.