Originally Posted by ReacueGreenJK
Worked fine yesterday, today after washing it it's way off.
I'm guessing here, but I'll bet when the temperature sensor dries off it will read as before.
When things are wet (such as just after washing your vehicle) the wet items are cooler while the water is evaporating. (That is how a "swamp cooler" works).
Hope your sensor is OK.
KG6SLC aka Eugene