Temp gauge reading zero, but flashing

[Wilf1234]

Hi guys
I have a 1985 T3 1.9 boxer petrol (water cooled).

Temp gauge is flashing but needle reading zero - coolant level is good.

I have a quick look round the forums, but is there an obvious place for me to start looking ?

[Shinnster]

i'm still learning myself but could be the coolant level sender? have had this issue myself and had to get a new one and it fixed it for me.
is it definitely connected securely? on top of the water tank inside the engine bay.

if its disconnected it would flash on the dash even if there's coolant in the tank.
if it is connected properly then maybe time to buy a replacement (assuming the wiring is all good)
 

[Robsey]

The "flashing when cold"..
Is that when you first turn on, or all the time the ignition is on?

If it is just for the first 5 or so seconds, then that is normal.

If it is all the time, then before you look at buying anything, the usual checks are:-
1 - Clean the earth crown on the left A pillar just above the fuse box.

2a - Check and clean the No42 or No43 relay contacts which also sits on the left A pillar near the earth crowns. (Only on earlier torpedo fuseboxes).
1985 van 'should' be the later CE1 fusebox.
2b - Consider a faulty Level Control relay (No 42 / 43).

3a - Check continuity of the coolant level switch with and without coolant in the bottle.
3b - Check that the switch probes are clean.
3c - If the switch still fails to operate correctly, then consider getting a new one.

4 - Check continuity of the instrument cluster ribbon.

5 - Check to see if the fuel gauge is also working fine.
If the fuel gauge is also erratic, then the voltage regulator may be faulty.

There is a very good thread somewhere on how the coolant level sensor (switch) and control unit (relay) work.

[Wilf1234]

Thanks for this - any advice as to how you carry out step 4?

Cheers