Mk1 Golf GTI

I'm looking for help with a problem….when I turn my ignition on the water temperature guage  immediately starts flashing and the needle shoots up to max…even before I turn on the engine .I am no expert but to cut a long story short …it is not the temp sensor or the guage  or the instrument cluster …any suggestions please…

There's only the wire left

I had this same fault on my 1983 GTi. It turned out to be the coolant level sensor relay.  Swapped it with another one and that cured it.  The relay is numbered either 42 or 43 and sits in a holder on top of the fuse box.  I think that only the 1.8 cars had these coolant sensors fitted?

gee920 said

I had this same fault on my 1983 GTi. It turned out to be the coolant level sensor relay.  Swapped it with another one and that cured it.  The relay is numbered either 42 or 43 and sits in a holder on top of the fuse box.  I think that only the 1.8 cars had these coolant sensors fitted?

Failure of the coolant sensor on top of the expansion bottle would set the flashing warning light off but not move the needle???

In my case it wasn't the sensor but the relay it's connected to.  When the ignition was switched on , the gauge would quickly go to full scale and the light would flash continually. As I said I replaced the relay and this fixed it.