Glow plugs not working after head gasket replacement

[CoalMarx]

Unfortunately i blew the gasket on my 1.7 diesel ky. I already had a problem with a buzzing dash and oil filter light, but then we lost the lights on the dash (still have the buzzing). Now the head gasket is replaced but the glow plugs won't light up even though they have been confirmed three times as all working. My dad is convinced its an electrical problem. Does anyone know what the yellow cable does from the engine bay on a 1.7 diesel? Apparently its for the low coolant warning on a 1.6td but a bit lost as to what it does for a 1.7. Thanks in advance for any help!

Sent from my SM-G960F using Tapatalk

[Mocki]

Wiring loom colours are the same on all vans , regardless of engine .
Yellow is oil pressure

Have a read here https://club8090.co.uk/wiki/Diesel_engine_wiring

[CoalMarx]

Ah, that looks very useful. Thanks Mocki.

Sent from my SM-G960F using Tapatalk