windshield wipers intermittent speed not working

[Medusalith]

The windshield wipers of my V40 work fine except if I want to use the slower/intermittent wiping speed which is not working at all. I went to the volvo service and they first replaced the control lever by the steering wheel but the problem persisted. They investigated further and told me the problem is in some electronic module that controls the electric fonctions of the car, and the repair would be: 625Euros(new part) + VAT + labour. I don't feel like kissing my Xmas budget goodby; can anyone help with some ideas to get this fixed, maybe this module can be repaired, does anybody have a clue? Is there a schematics of the windshield wipers?

All help appreciated!