2.25 diesel glow plg voltage

Just measured the voltage at the glow plugs and all were 1v ! I take it thats wrong

Is there a common fault or is it a new resistor time

Doesn't the voltage drop as they heat up? (or were you measuring cold?)

thats was from cold ?

Are they in series or parallel wired?

erm a wire goes from the first then another wire to the second etc ?

That sounds like in series then. If there's only 1v at the first plug from cold - that's bad.

Is the relay ok?

the resistor is the only bit of electrickery I could find ?

Ah, ok. Just looked the wiring diagram and my relay is (another) non-standard addition.

According to this diagram if the resistor fails then the cold start light should be bright. If you haven't got 12v at the bulb/resistor then could it be the ignition switch?

Are you measuring the voltage between to top of one and the top of the next, or are you going to a good earth?

SpringDon said:

Ah, ok. Just looked the wiring diagram and my relay is (another) non-standard addition.

According to this diagram if the resistor fails then the cold start light should be bright. If you haven't got 12v at the bulb/resistor then could it be the ignition switch?

Click to expand...

nothing from the ignition switch so user a jump lead from battery to resistor to get some power there.....1v !

Oldseadog said:

Are you measuring the voltage between to top of one and the top of the next, or are you going to a good earth?

Click to expand...

top of glow plug to engine block earth

Stupid question but have you got 12v across the battery?

If you have a multimeter , is the resister open circuit? Sounds like it might have failed 'though.

And another thing (apologies if this patronising) but it's sometimes best to use a bulb and wire rather than multimeter which can give you phantom voltages. The bulb will tell you if it can run a load.

SpringDon said:

Stupid question but have you got 12v across the battery?

If you have a multimeter , is the resister open circuit? Sounds like it might have failed 'though.

Click to expand...

yes battery is nearly at 13 ! as is brand new....how do do I test the resistor please ?

If you are using a multimeter then does it have an ohm setting. If so then put the probes each end of the resistor if it reads infinite or very high, it has failed/gone open circuit.

If no ohmmeter - use a lead from the battery and a bulb on a wire. Earth it from the ignition side of the resistor and you must see the bulb light up. Earth the bulb from the other side of the resistor and if it's ok the bulb will light more dimly. If it doesn't light the resistor is u/s.

on the ohm part of the meter I am getting a reading

And the reading is?
Actually I don't know what it's supposed tobe but if it's less than infinite, I guess it's ok.

If it seems ok, you are going to use a bulb to find what's dragging the load down. It might also be worth testing the glow plugs individually.
Failing that, i'm running out of ideas. Hopefully a grown-up might be along to help soon.

SpringDon said:

And the reading is?
Actually I don't know what it's supposed tobe but if it's less than infinite, I guess it's ok.

If it seems ok, you are going to use a bulb to find what's dragging the load down. It might also be worth testing the glow plugs individually.
Failing that, i'm running out of ideas. Hopefully a grown-up might be along to help soon.

Click to expand...

ok mate I appreciate your help.Bulb test tomorrow

Best of luck!