Menu stops functioning on LCD when more than one analog input is used

I am using a UNO R3 with a SainSmart LCD Keypad Shield V1.0 and SainSmart 4 Relay module as a temperature controller to read 2 thermistors and run 2 pumps. The board is powered from a 10V 0.85A power supply, that also supplies power to a 5V regulator that powers the thermistors to be read by the analog in pins. See diagram. The LCD has a menu system for adjusting variables, and one option to display the current temperatures. Everything work fine until I hook up more than one of that analog inputs. When I do the lcd display will not enter the temperature display screen, it just stays in the menu. Everything functions fine, but I really want to be able to display the temps. Any help would be much appreciated.

Temp_Cont_Software.ino (10.9 KB)

Can you clarify:

It works if you hook up only the glycol sensor it works if you hook up only the tank_sensor It fails if you hook up both?

Are the any electrical connections at the sensor ends of the cables to anything?

That is correct: It will work if I hook up the glycol sensor only, it works if I hook up the tank sensor only. When I hook up both it typically does not allow me to exit the menu into the temp display, and to make it more confusing it occasionally does after a long delay, but it is inconsistent.

I am not sure what you mean about the eletrical connections. The analog pin is between the fixed resister and thermistor.

voltage---resistor---|---thermistor---Ground to analog pin.