Ehh, I don't worry about getting any of that stuff wet. I don't use a pressure washer though.
I'll just use a brush and whatever soapy water I have left after washing the rest of the Jeep. Spray it down to wet it (maybe let it soak in your case), then brush away to clean off the junk. The electrics are sealed up well enough for normal hose spray and water won't hurt the alternator either.
08 Limited Hemi - wheels, tires, springs...ya know, stuff