I power wash all my vehicles, off road vehicles and even the trailer when I'm finished with them. A light spray on engines then let them run for 5 minutes till they warm up.
As far as water getting into electrical connections: If you drive in the rain, drive through puddles, water sprays into your engine compartment. i have yet to have an electrical issue.
Now, I don't use an open water hose and douse the wires but washing with a light spray after a little simple green is nice.
Sold my 08 Jk a few months ago, removed all carpets and seats and power washed the seats and using compressed air blew them dry, sat in the sun for a week and looked brand new.
New owner was very impressed, I got top dollar and my '19 Jl Rubicon sits in my garage.