I just finished my DIYPNP build, and I noticed when I power it from the wall without it being hooked up, my temperatures randomly spike. Is this normal or should I look for something to be messed up? I ask, since the car wouldn't start when I hooked it up for the first time today, and I want to rule out things. I'm thinking its a setting somewhere that's not right.

 

The temp inputs are floating without sensors hooked to them. The readings will normalize with sensors installed.