Click, Click, Click

[4rd Xplora]

Have a clicking noise in the console similar to the clicking you get when the blend door motor gears go belly up. The noise seems to be coming from under the CD player. Found the power connector pluged into the rear A/C control head that was pointed out in another post. Did some low tech engineering and found four wires showing power with the connector inserted into the control head and three when unpluged so I knew these were power in and the now dead one was power out. When unpluged there was no noise so I knew power came to the control head first and then to whatever was clicking. Short story is I cut the "dead" wire hoping it was the power to the clicking part and pluged the connector back in an no more clicking and everything works (blower motor, lights, radio controls and upper/lower vents control). Now for my questions, the related post stated this was a blend door. Isn't the rear hvac just a "piggyback" style unit? I mean doesn't it simply have a air duct that runs from the front air vents and a blower to boost the flow? So why have a blend door in line? BTW whatever's clicking, looks like the complete console will have to be pulled to get to it. And what could be clicking? Anybody ever deal this?