Most intermittent wipers have a timing device or a relay that operates off of a RC control circuit. Try turning on the wiper without the engine running, set it to some delay factor and then see if you can hear a relay clicking anywhere in the car. Then check the fusebox and listen there as well, if you hear a relay cycling then it is most likely something wrong within the motor assy. Look at the diagram for the fuse box, it will generally tell you which fuse/relay controls which circuit. If the pump is working as you describe, then you most certainly have a control problem. Let me know..
1987 BMW 325
[This message has been edited by jeffsr (edited 02-03-2000).]