Where is glow plug relay on a vito cd111long?

The glow plug relay on a Mercedes-Benz Vito CD111 Long is typically located in the engine compartment, often near the battery or the fuse box. You may need to consult the vehicle's manual for the exact location, as it can vary by model year. It's usually a small, rectangular unit that can be identified by the wiring harness connected to it. Make sure to disconnect the battery before attempting any inspection or replacement.