red flashing temp gauge

[gillinghamfishing]

hello when i started the van today the flashing temp light stayed on,i turned it off tried again and it was fine. i drove home and it stayed off until i pulled on the drive and it started flashing again.the temperature is fine the needle never even reaches the light,not even halfway and the expansion tank has water in it, any ideas , should i not worry too much or could it need looking into a bit deeper thanks spencer

[Titus A Duxass]

Engine type?

[Mocki]

IS the header tank full to the brim?
if it is, and temp wasnt silly, then its either a wire issue, or the sender in the top of the headertank.
Also check the earths , both in the engine bay, and the ones in the cab, behind the fusebox, and the one down by the heater outlet.

[gillinghamfishing]

thanks for the replys, its a 1.9 petrol and the tanks are full up so ill have to check the earths thanks again spencer

[clartsonly]

check the crowns behind the fuses, mine does the same it makes no difference whether you are shorting the switch in the water tank, I think the connection is broken before it even gets as far as the sensor in the tank.

[Aidan]

top tip, poor contact on fuse board for the relay caused by condensation/damp/water ingress as per earths, remove relay and put back in, worked for me, weak signal causes flashing when hot - it's the no.43 in socket 3, but you can pull them all and put them all back won't do any harm, mechanical cleaning of contacts