Temp reading is wrong?

So my 3.1 printer committed suicide the other day and I came hone to the glob of Death. My extruder could not be saved so I decided to take the opportunity to upgrade to the BETA2 tool head. Now that I'm finished putting it together, I finally fired up the printer and Klipper and my extruder temp is reading 158° despite having not even tried to heat up my hot end. Before noticing this, I tried to heat it up and got a shutdown due to "extruder not heating at expected rate." But my hot end is cold to the touch, yet still reads this high temp. Any idea what I did wrong?