Hey pullo there are far more others versed on this site about Thomas pumps than me. Lets wait and see what someone else may have to say? Sounds like your not getting enough juice to it if you can turn the fan by hand and then it starts to work??? Lets see if someone else will chime in and be able to help you.
RC51 is exactly right. The blue and brown are your hot and neutral wires, the other to black wires go to to a capacitor. I had the same problem the other day. There aren't any ground wires, so you will need to plug it into a GFI outlet.
I'll try and post pics later if I can figure out how.
