Flashing engine temp light

[red]

Just picked up a 1990 mk2 gti 8v.

However the temp guage doesnt work and during the test drive and about 20 miles into the 35 mile drive home the temp light came on and was flashing the rest of the way home... Is this likely to be one of them blue/black sensors infront on the block or something else?

[rubjonny]

temp gauge runs off the black 2 pin sensor on the front of the block, check the right plug is connected as well, its the one with a red/yellow wire. the light could have been caused by the faulty sensor, or it might be down to the level sensor in the tank. check the coolant first
If the level is ok, pull the plug and bridge the pins with a short length of wire. if flashing stops the level sensor is bust, if not its a wiring or temp sensor fault.