from what i have read you can test the sensor to a degree as it has a diode between vcc and ground. I have a waterproof version it has 3 wires black, red and yellow now my assumption is that black is ground, red is 3.3v and yellow is the signal. i put my meter on diode mode put red probe to red wire and black probe to black wire and nothing is displayed on my meter if i the revers them round my meter displays 530. im trying to figure out why when i wire this sensor in its stops the pi from powering on? i have a 4.7k resistor in place between red and yellow. The only one i had available was a 2watt version could it be the resistor or is the temp sensor not correct??