I wonder if someone can offer advice.

Car worked fine 3 days ago. Left car outside - snowfall, snow melted. Now the car won't go. The engine turns over but won't start

• Worked OK 3days ago - no signs of any problems before
  
• Noticed that when I turn on the ignition the glowplug warning light doesn't come on
  
• No other noticable warning lights indications of problems

I have:

• checked the fuses (both next to the drivers facia and by the battery)
  
• applied WD40 to the wiring and connections
  
• removed the cables to the glowplugs and applied WD40
  
• checked the battery

All seemingly OK

Can someone help tell me how to test the glowplug and what to look for next if they test OK? I'm not very experienced with cars so would appreciate simple descriptions/advice.

Many thanks in advance

Maybe the relay?

Update:

If anyone can suggest/comment on what I've done -

Cause is Immobiliser?

- I've used the spare set of keys, still doesn't work - rule out immobiliser

Cause is fuel related?

- Turned ignition & saw fuel in clear pipe from filter move - rule out the fuel system

Cause is relay?

- There don't appear to be any other problems, I've been told by a Skoda garage that the relay for the glowplugs also serves other electrical parts, I should have seen other problems - unlikely to be relay

Cause is Glow plugs?

-I've connected a multimeter between the glow plug and cable and no voltage when I switch on the ignition - maybe, but since power isn't getting to them leads me to suspect:

wiring

Does this make sense? and if so, what should I do?

Thanks

Does anyone know the part number for a Skoda Octavia 2005 1.9TDI glow plug. Are there any other equivalents from Bosch etc available?

I believe the glow plugs are not used above low temperatures in which case you will not see any volts on the glowplugs in summer.

Anyone confirm?