1998 Alhambra 1.9 tdi, 90 bhp (AHU)

[jugs1960]

Hi
I'm having starting probs, traced fault to no feed to glow plugs, checked relay also ok, but found that relay isn't getting earth signal from ECU.
Can any body tell me what gives the ECU the signal to tell it to earth the relay, I have also checked the resistance at the coolant sensor at varying temps and the sensor seems to be ok. Many thanks in advance
Jugs:confused:

[Crasher]

When you have made 5 posts, PM me the cars reg number.

[kenney]

It is the temperature sensor,which feeds the ECU with the information for cold starting.