89 Eagle Premier

My climate control temp displays 00. They selector switch works, fan works, but can not get the temperature to change at all. I have a service manual for the premier and went through the trouble shooting chart. I went through the 4 modes (low, M1, M2, High) In M1 mode, Max & Norm light up saying I have a open wire in car temp sensors or short to ground in temp sensors but when I go to high mode both Norm (outside temp) and BI/LEV (in car temp) display the temperatures fine. I am assuming that I do not have a short or something ground. :screwy: Anyone have an idea to resolve this? Thanks Indy9727