Checking the electrical current supply
First check on a vehicle manufactured after August 1977: has the blade fuse blown?
This 50A blade fuse is located between the engine compartment and the water tank (see arrow) in diesel cars manufactured after August 1977. Here you can see in the photo: the cover has been removed from the small block where the fuse is located. If there are problems with starting, you should check this fuse.
If it has not burned out, connect an electric test lamp between the ground and the connection of the red-white wire at the glow plug of the 4th cylinder.
Remove the wire from the engine temperature sensor (released only after August 1977).
Turn the ignition key to the "Pre-glow" position; the indicator light should now flash.
If it burns, then the defect is probably in the glow plugs.
If the bulb does not light, you need to look for a defect in the pre-glow relay, in the starting switch and glow switch, or in the central part of the electrical equipment.
Reconnect the engine temperature sensor cable.
Checking the relay and the central part of the electrical equipment
Left: glow plug relay (released before July 1977). Right: design after August 1977. The newest relay has an additional terminal 50 - this is a distinctive feature. The glow plug relay of the fast glow system has the same contact arrangement as in the right figure
Connect the clamp of the electrical test lamp to the ground.
Using the tip of the test lamp, touch the contact tab of terminal 30 at the pre-glow relay.
If the light does not light, the circuit is open: either a break in the wire leading to terminal 30 of the central part of the electrical equipment, or in the central electrical equipment itself.
If the light comes on, the fault may be that the relay is not working and therefore the current line to the glow plugs via terminal 87 is blocked.
Connect the test lamp to terminal 86 of the relay.
Turn the ignition key to the "Pre-glow" position.
If the control lamp now lights, then the wire leading from the starter and glow switch is OK. Then the defect is that the current line from terminal 86 of the relay to the "ground" is interrupted.
Try shunting with an insulated piece of wire.
If this does not help, then the relay is faulty.
If the bulb does not light, either the glow plug starter switch (terminal 15), the supply wire, or the central part of the electrical equipment is damaged.
Visitor comments