Hi all,
I have a 2.0 litre HdI 406 YEAR 2002. I noticed the car was getting hard to start. I changed the heater plugs and it made no difference. I then started to investigate further and noticed that there is no current traveling to the plugs at all. Does anyone have a wiring diagram or know where this circuit is fused or relayed ? or have any other ideas to where the problem lies ?
Thanks
Tom.
No Current to heater plugs
Moderator: RichardW
No Current to heater plugs
Regards
Tom Faughnan
Tom Faughnan
Hi Tom -
Usually there is no fuse in this heavy current circuit as the 4 plugs would consume close to 50Amps total when heating.
Follow the heavy gauge wire backwards from the glowplugs until you find any relay/electronic box.
That will be your glowplug timer control box.
This box/relay is commonly suffering from burnt/corroded wire connections precisely on that heavy gauge wire - and its mate coming from the battery +12V distribution point.
There is simply a relay make contact between these 2 wires.
The relay is in turn controlled by a small electronic circuit with temp sensors on the surrounding air and the engine block to decide the glow time.
Or the relay may be controlled by the engine management computer.
Usually there is no fuse in this heavy current circuit as the 4 plugs would consume close to 50Amps total when heating.
Follow the heavy gauge wire backwards from the glowplugs until you find any relay/electronic box.
That will be your glowplug timer control box.
This box/relay is commonly suffering from burnt/corroded wire connections precisely on that heavy gauge wire - and its mate coming from the battery +12V distribution point.
There is simply a relay make contact between these 2 wires.
The relay is in turn controlled by a small electronic circuit with temp sensors on the surrounding air and the engine block to decide the glow time.
Or the relay may be controlled by the engine management computer.
Anders (DK) - '90 BX16Image
your first check should be atglow plug timer relay disconnect multi- plug at timer relay with ign on you should have 12 volts at pin 3 on muuti plug [ centre pin] pin no 1 onmulti -plug is your earth pin on the rear of multi -plug there are two heavy wires one of these has apermanent 12 volt feed ign off or on the other heavy wire goes to glow plugs if you have voltage as above and your earth is ok then you either have a faulty glow plug timer or bad connection faulty wiring between glow plug timer and glow plugs hope this helps reguards paul
I doubt your problem is due to faulty heater plug operation as the 2.0 HDi engine doesent need them unless its really cold, they are used more for post heating than pre heating. If i remember rightly on this engine they come on for half a second at 0 degrees celcius, so above 0 degrees the ECU wont even send the signal to the glowplug relay to tell it to switch them on. You could easily prove if it was a glowplug issue by using a thick peice of wire straight from the battery to the glowplug rail for a few seconds then try & start it.