HELP ON REPLACING BLUE FULL BEAM WARNING LIGHT

Can anyone help me in the best way to rectify my Blue Full Beam Warning Light on the dash as it's not working, I suspect the Bulb may have gone, as
the full beam is working perfectly. Any advice would be fantastic, thanks

Knowing the make and year helps me out….at least to test the wire to the cluster as if that isn't getting a signal to the dash, then the light won't come on, or it could be a bad bulb…. but lets check things about first.

H Briano 1234, I have a 1989 Mk1 Golf Cabriolet, chassis number 013165, thanks for helping me out

Check this;
https://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=technical%2Felectrics_2%2Fmain-beam-led-tell&kfs78=60

I will only add to tell you to take great care manhandling the mylar on the cluster. and going back replace all the illumination bulbs that is the 2 for the cluster as well as the single lower for the MFA/Clock.

The other piece of advice I have for you is to "plump' your connector and add an addition ground to the clusters main connection as you will have a lot of less flakier things happen.

Improving your Cluster Connections and ground. | Volkswagen Owners Club Forum

I would check the blue/white wire on pin T14/9 on the cluster to verify that you are getting a positive voltage there when you flash the high's as if that isn't there then your issue isn't with the bulb.  You can also use a 9VDC battery with the Positive on pin 9 and the negative on pin 2 (brown) and once connected the bulb should flash as if it doesn't then you have a blown bulb.

changed the bulb in mine, but still wasn't working, sometimes used to work on its own so I think it might be dirty contacts on the stalk.