The glow plug relay on a 2005 Ford F-250 Power Stroke is not a single, easily identifiable relay like in some vehicles. Instead, the glow plug control module (PCM) handles the glow plug function. There isn't a separate relay to replace. Any problems with the glow plugs themselves or their control will likely be diagnosed and addressed within the Powertrain Control Module (PCM).
Therefore, you won't find a "glow plug relay" to replace. If you're having glow plug issues, you'll need to diagnose the problem using a scan tool to check for codes from the PCM. A mechanic with diagnostic equipment is the best resource for this.
