Where is the glow plug relay located on a F-350 7.3 diesel engine?

The glow plug relay on a 7.3L Powerstroke in an F-350 is typically located in the Power Distribution Box (PDB), also sometimes called the fuse box. This box is usually under the hood, near the battery. However, the exact location within the PDB can vary slightly by year. You'll need to consult your owner's manual or a wiring diagram specific to your truck's year to pinpoint the exact relay. The diagram will show the relay's position and typically label it as the "Glow Plug Relay" or something similar.