Need some advice please...............

As Boxer instrument clusters have a reputation for internal failures that cause other warning lights to light up dimly, I would think this is most likely to just be another manifestation of the same problem in a slightly different form.

A warning light like that is designed to be either on or off so, provided the illumination test when you first turn the ignition on shows full brightness, I wouldn't be worried about it too much if it were mine. I guess longer term the fault may get worse and you might have to get the instrument panel repaired, but it sounds like you may have a while before it's anywhere near bad enough for that.

As a precaution, at next fuel filter change I would try emptying out the complete fuel filter and see if there is any water present - but I would be surprised if there is.

Ian
its easy to drain to check if you have any water in the filter
has your van been parked up or have you been driving your van

Ian
From been park as you have said and why I asked you would have been getting a lot of moisture build up and even more if you don’t have a full tank of fuel so is a good chance you have started up and pulled this into the filter .but will need draining or will do a lot of damage if it goes to the pump and injectors. The wiring has lots of problems from the water coming off the screen and down onto the wires by the ecu . I have had to repair lots of damaged wiring here and is why  I have said about extra drain holes in the grill below the windscreen to help this problem .