Let me add two things; first, is there anything about redoing the cooling system which would affect the blower? Any type of sensor or something? Does the engine temperature have to reach a certain point?
Second, at one point I held the rpm's at about 1800 for a few minutes. After a while, it sounded like there was water gurgling just under the front dash. That went away after a minute or so. The noise of the engine also seemed to increase as if a cooling fan had kicked in or a pump had started. That sound continued until I let off on the accelerator. Once the car was back at idle, that sound went away. Does any of that sound in anyway related to the blower motor?