Poor windscreen wiper pressure

I have suddenly started having poor pressure in my windscreen wiper spray. Vehicle is 4 years old and travelled 60000 kms. I have had a look at the 2 spray heads (just under the bonnet) and there appears to be electrical wires plus the water pipe going into each one.
Do they each have a pump?
If someone can tell me how to check out the system i would be grateful!
Many Thanks, Jim