Hi

Can anyone help with a problem on my 1997 6N Polo 1.6 auto.

The coolant level/temp warning light flashes constantly when the engine is running.

The water level is correct and I have checked that the cooling fan cuts in and out when the car is at idle and not moving

I have a brand new header tank which I have filled to the correct level and connected up, but the light continues to flash !

Anyone have any ideas

voxy53

Coolant temp sensor possibly.

Hi

Thanks for the advise

Have just ordered a sensor on ebay, so will see what happens when I fit it.

It was only £5.99

Cheers

voxy53

Check the wiring to the sensor on the header tank. If you unplug the sensor does the flashing stop?

Hi

I have tried unpluging the sensor on the header tank, but the flashing carries on as before !!

Voxy53

Hi

I got the new temp sensor today so I thought I would quickly connect it up without taking the old

one out. I took the connector off the existing sensor and connected to the new. Started the engine

and 20 or so seconds later the light on the dash is still flashing !!

Anyone any more ideas please

Voxy53

Dissconnect the connector for the level sensor, and short pin 1 (blue/Red wire ) to the battery NEG terminal or the chassis/engine block, if the light continues to flash this will eliminate the low level sensor and it must be the coolant temp sensor/wiring, but if does'nt flash then the low level sensor/wiring is at fault

Dissconnect the connector for the level sensor, and short pin 1 (blue/Red wire ) to the battery NEG terminal or the chassis/engine block, if the light continues to flash this will eliminate the low level sensor and it must be the coolant temp sensor/wiring, but if does'nt flash then the low level sensor/wiring is at fault

Hi

I have tried your possible fix, but the light continues to flash !!

Looking at the wiring diagram in the Haynes manual, the coolant level sensor is wired directly to the warning light in the instrument display

It may be that the control unit in the display is faulty ?

I may take a trip to the breakers and get a new one

Worth a try ?

voxy53

Dissconnect the connector for the level sensor, and short pin 1 (blue/Red wire ) to the battery NEG terminal or the chassis/engine block, if the light continues to flash this will eliminate the low level sensor and it must be the coolant temp sensor/wiring, but if does'nt flash then the low level sensor/wiring is at fault

Hi

I have tried your possible fix, but the light continues to flash !!

Looking at the wiring diagram in the Haynes manual, the coolant level sensor is wired directly to the warning light in the instrument display

It may be that the control unit in the display is faulty ?

I may take a trip to the breakers and get a new one

Worth a try ?

voxy53

If the light continues to flash then it's the temp sensor/wiring possibly at fault, the level sensor is'nt wired direct to the warning light it goes into the microprocessor in the instrument pod and it decides to flash the light if either the temp has excceded a certain level or the coolant sensor resistance is below a certain level.

I'm not sure where the sensor is earthed but this is a possible cause, or perhaps there is corrosion in the connector. Have a look, if it's greenish then it needs cleaning with small flat head screwdriver. Also the connector to the clocks could be at fault or perhaps there is another connector between the sensor and the clocks that could be corroded. This should be shown on your wiring diagram.

HTH

Hi

Thanks for all the info

I had a look in the haynes manual at the wiring diagram, and had a thought that the instrument panel could be at fault.

I went out to the local scrapyard and got a new (old) panel which I will try to fit soon

See if this cures the problem

There seems to be a lot of electronics inside

I will let you know whether this cures the problem

voxy53

Hi

Just to keep you up to date, I have replaced the instrument panel with the one from the breakers, and low and behold the light is STILL FLASHING !!

I have replaced my original head and will now check the wiring to the water level sensor

Cheers

voxy53

These are the diagrams from Elsawin not dodgy Haynes ones!!