Temperature Warning light

Hi Guys/Girl

The red high temperature alarm light located at the bottom of the dash temperature gauge is always ON, the temp indicator works fine.

Is the Alarm light on the same circuit as the temperature indicator or a separate switch?

If its a switch where is it located?

If its from the same sender behind the radiator (single wire) how does the circuit work

Thanks

Guy/girls

Angus

Not sure if an 84 cabriolet is the same as mine 1988 car as I've a different layout on the instrument cluster, on mine is a low coolant level sensor and the sensor is on top of the radiator expansion tank.

Looks like this.
https://www.ebay.co.uk/itm/334937759155?fits=Plat_Gen%3AMK+I%7CModel%3AGolf&hash=item4dfbd89db3:g:ZbAAAOSwS8dkpPEc&amdata=enc%3AAQAIAAAA8BBW8ajAVfymO8is%2B9qhN%2BIg1mBPZhoXoxf6VBmYH8ug6dIerJlvapdeFqCp5TSwPezGSaXvN3501WF%2B8COQc3n7JMlxSXYr9vYseqEwLiOBnBJQTJLqVsxFl4wnvRsrnGbQ1t7%2FdqOnmBW9xeD5h5aOP716NU1CIBYRLaRSLAEoWIW46H9eD%2Fes64G0AsjRhYYw8Ne%2F5mwOX1q2A4bBWN8GjrycbiED258hZw8FksPSe7aDYE6MMgX11%2FQ5xnr8YPj%2FU8p7nE%2FbqzoGc3ayaoeH4LzRUK6uDRhMc5w3cpEo0zcyNfS7bbfMyDTADmuSew%3D%3D%7Ctkp%3ABFBMnIC17txi

My instrument cluster is like the one in this thread on fault finding the flashing light.
https://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=big-block-injection_2%2Fcoolant-level-sensor_3

Darren/Angus said

Hi Guys/Girl

The red high temperature alarm light located at the bottom of the dash temperature gauge is always ON, the temp indicator works fine.

Is the Alarm light on the same circuit as the temperature indicator or a separate switch?

If it's a switch where is it located?

If its from the same sender behind the radiator (single wire) how does the circuit work

Thanks

Guy/girls

Angus

Just looking at those clocks, they appear to be from a hatchback. The yellow high beam colour is usually blue in a cabby. My 1984 GTI is blue and many others I've checked have been similar.

Have you checked your earth on the rocker cover? If it falls off it causes dash issues. It should be a brown wire attached to the rocker cover. If you can't see it, it's probably hanging down in the bay somewhere.

Fingers crossed for an easy fix! 🤞

Mine is an 83 grid cabby and has the same clocks with yellow high beam. I know in 84 they switched to blue high beam led so clocked should be fine and just might have been a cross over. Regarding the temp issue, if it's a a coolant level sensor problem the needle will usually go to max. I'd be be tempted to change all the temp sensors initially as there not much money. 

If you have a coolant level sensor in the expansion tank, the sender tips can get scale on them and not read the level of the coolant in the tank correctly.

Remove the sender clean the probe tips, besure that your a/f to water is a 50/50 blend.  Too much a/f to water and your sender will have issues.