My son's car was recently in a storm and the windshield was damaged, water made its way in the dash and now the ac control won't power on. It's only 3 wires to the unit. I have 12v battery, a good ground, the third wire gets 3.8v when the key is on (and drops off with the other dash lights after the key is off) is this 3.8v a Normal voltage and if not where is it fed from? Suggestions please, Thanks!

 

Sounds low to me. Might be the panel control got damaged. Might want to test it out. Does it work properly on any other mode?