newbie - where to start with temp lights flashing

[surfcarrot]

hi I am new to here and have got the temp gauge lights flashing problem.

I have searched the wiki and reads lots of posts on this but don't know where to start

this is what I do know...

Lights used to flash 10 mins into a journey
Lights now flash straight away and for whole of journey
The temp gauge 'stick' on dash does not work anyway
The top up tank level is between min and max when cold (but we have topped up with antifreeze a month ago to cure problem)
The main tank (expansion?) level looks ok
The heaters inside do kick out warm air
The fan at front of van does come on sometimes
I cannot see any visible leaks (but have only looked under van after it has stood)
Van is 2.1 inj. Caravelle with DJ engine

Any simple advice appreciated (I am not too confident with mechanics cos if it aint broke I normally break it )

[kevtherev]

I take it the header tank is FULL to the brim?
take the level switch out and clean the prongs (unscrews)
or clean the connections
or take the level switch out and change it

[surfcarrot]

I don't think it was full to the brim.
I will check tomorrow when wife gets back from work in it.

[kevtherev]

eerr
red lights flashing ...means STOP and fix it

do you ignore red traffic lights?

[tannera34]

Hi,

Not sure whether this is the reason but in fixing our gauges we found almost all the faults came down to earth connections (they are all over the place) that had corroded and lost connection.

The temp gauge can be tested by shorting some relay contacts (look on the forums I found it in here somewhere). Once you know the guage works trace the wire back for connectivity (multimeter and long flying lead) and then look at the earthing. If the engine has been worked on and the temp gauge has had a standard gasket (or cardboard one!) then it will not be earthed to the block. VW produce a metal interior gasket one to earth properly, but most of these engines have been out at least once! The easiest thing to do is run a seperate earth to the sensor housing to fix.

It is more likely to be wiring than a faulty sensor. If you have to change the sensor be very careful the quality of the new ones is VERY poor (thanks VW) and you must be VERY VERY gentle putting it in.