Car wiring diagrams: Ford F350 Glow Plugs Wiring Diagram, wiring diagram, wire wiring harness, schematic circuit diagram, wiring diagran, wireing diagram, wirring diagram, wiring daigram, wiring diagrams. Does anyone know where I can find the wiring diagram for the glow plug relay on an early PSD? I m not sure if mine is wired correctly...sel Forum The.selStop.com > Fordsels > .L IDIsels Not Power Strokes > glow plug wiring diagram .[ QUOTE ]This is not a glow plug relay it s the MIAH, Manifold Intake Air Heater, relay. The silver box with the fins behind the MIAH relay is your .