Hello all bought a 2005 chrysler pacifica limited two weeks ago and I was looking under the hood today and found this, look at the picture below. What is it? I know is a switch, it came with the car or somebody put it there.

 

prob for an add on to something that needed battery juice fallow the wire u will see its not factory though

 

turn it off and see what happens?

 

Actually that switch was off since I bought the car, and the car runs fine except for codes p0480 p0406 which involves cooling fan 1 control circuit and egr sensor a circuit high.