AC compressor always on

I have a 1998 Ford Taurus. With AC on, the compressor
used to cycle on and off.

It stop doing that recently. Now with AC on,
compressor remains on and never stops.
I've noticed the following:
- air is cold.
- no ice up observed.
- I have a mechanic check the high and low pressure
and I was told it is normal.

Is this normal ? If not, anybody have any suggestion
where I should be looking at next ?

Thanks !!!

it depends on the ambient temp as to what pressures are going to be but it should cycle eventually!~