Thanks, but the CCU is a new reman. The last one that I got from them (in my other SDL, works flawlessly), but I will still keep in mind that even new can fail.

The vents seem to be a logical place to look but the confusing part is that at max cool, their is still heat, but the monovalve is suppose to be closed, thus not allowing hot coolant into the heater core, yet, I have heat.

__________________
87 300SDL - 215K Miles !!
99 F-350CC Dually PSD - 190K
86 300SDL - 189K
All on B-100