racthree:
I initially was using Relay: SRD-05VDC-SL-C (How to Set Up a 5V Relay on the Arduino - Circuit Basics)
What on earth was wrong with using that relay module if you already had it with you?? why did you switch to the bare relay sugar cubes??
racthree:
I wonder if it is too much load on Arduino to have a temperature sensor, and then the LCD display. if I need to have the pin to have a High +5V?
Arduino i/o pins cannot supply enough current to drive a bare relay sugar cube anyway, whether you have additional components like a lcd display or not. Which is why you should use a transistor or a mosfet or get a ready made 5V relay module that takes logic input.