The engine must be cold when checking (ambient temperature), battery - fully charged (voltage not less than 11.5 V).
Checking the power supply
This check is performed with the glow plugs installed.
1. Remove the top engine covers, refer to Section Removal and installation the top engine cover.
2. Disconnect the glow plug connectors, for example using the special clamp HAZET 4760-5.
3. Turn on the test lamp between the cable contact and ground.
Material based on data from the portal: www.MercedesMan.ru
4. Turn on the ignition, warm up the engine. Leave the ignition key in the pre-glow position and watch the lamp. The lamp should light. Similarly, check the power supply to all glow plugs.
5. Connect the glow plug connectors.
Checking glow plugs
1. Apply an ohmmeter to each glow plug in turn and check if electrical current flows between the cylinder block and the glow plug.
2. If no current flows (0 W), the glow plug is damaged and must be replaced.
3. Connect the glow plug connectors.
4. Reinstall the engine top covers, refer to Section Removal and installation the top engine cover.