If the control lamp does not light up and the engine starts, check the lamp and replace it. Otherwise, the following check must be carried out with «probe»:
- disconnect the relay connector and turn on the ignition;
- connect «probe» to both pins of the socket. If the lamp does not light up, check the wiring. Lamp «probe» must be known to be correct;
- If the engine does not start and the indicator lamp in the instrument cluster does not light up, the following checks must be carried out:
- 1) check the integrity of the fuse;
- 2) turn on the ignition and check for voltage at the terminal «15». To do this, check the wire of the small plug connection;
- 3) disconnect the large plug of the wire going to the candles from the relay;
- 4) one end «probe» attach to «mass», and others - connecting in turn - check all relay contacts. The glow plug control device operates after the ignition is switched on, and voltage appears on each contact. Remember that it is necessary to switch the ignition off and on again from time to time in order to keep the heating device in operation;
- 5) if the test results are unsatisfactory, replace the relay.
Glow plug failure is determined by the engine if it starts, but not all cylinders are working. The non-working cylinder starts to work with a delay, since diesel fuel tends to self-ignite.