Outer Limits 4x4 Board

I have an 1992 80 series with a 1HZ motor.
Yesterday when I went around a corner a dash light came on as well as a high pitched alarm.
Over the past 24 houyrs is has got worse, comming on more often and staying on longer.
The dash light looks like an orange square with a droplet off the bottom - I'm assuming some sort of fuel alarm.
I have cheked all fluid levels etc - everything seems fine, tank is 3/4 full and the car is running normal.

I've tried to find some reference to the light on the internet and in workshop manuals but can't find anything.
Can someone help?

Thanks
Dave

is it a diesel, water trap in the fuel filter needs to be emptied

Thanks - seemed to fix it.
Fuel filter was replaced recently, must have got some bad fuel somewhere.