A little heater help.

[70RedBlurr]

Have not been able to get heat out of the heater in my truck. Blows air but just not hot, I think one time I got heat out of it but that was it after that. I have played with the control knob with no luck. I have done a search in the forum and read that it maybe wrong heater hose connection and maybe some cable in side maybe out of whack. I figured I would start with the heater hose connections and eliminate that problem first. Here is a picture of what I currently have going on...



I also read that my heater core could be upside down. Starting at the heater core the fittings are 3/4" for the top and 5/8" for the bottom fitting. I have a fitting that comes out of the top of the water pump and the last fitting I have is on the radiator itself, and the sizes for those are 3/4" on the radiator and 5/8" on the water pump fitting. i have read connect the two sizes together and also skip the radiator and go into the manifold, but I have a temp sensor in that location. Any help would or clues would do and hopefully get me toward getting heat to the inside of my truck.

Steve