This one is about the CCU. I have AC and heat, but the fan works when it feels like it. I read how to work on the CCU and to check the solder joints and they were all good with no breaks. I cleaned them all. and noticed that on the back of the board two traces had gotten hot or broke somehow, these were on the same side as the temp wheel. and at the back of the board. I resoldered the traces to where the came and went to make a connection. Fairly easy job.
I re assembled the CCU and re installed into the dash, bput the radio back and the ashtray and buttoned it up. I started the car and all was well I rolled the temp wheel to the coldest setting and I heard a motor running slowly in the passenger side under dash. I rolled it the other way to most heat and I still heard the motor running. If I rolled the wheel to the mid setting(26) it quit, if I then pushed any of the buttons it came back on. If I centered all buttons it goes off. What have I done, and what is running. I isn't the fan because there is no air flowing out of any vents.

Every once in a while the fan will come on with the AC running ...or the heater. I think this model has an aux water pump for the heater. Is this what I'm hearing running?

I figure that it is time to replace the CCU?