Today was the first warm day after a snowstorm which means car wash day, so I got out the pressure washer and washed the truck. I use a 20°nozzle on the machine and I don't get very close but apparently there was enough pressure to make it into the cab. It doesn't look like a ton of water and I've never noticed this before but clearly its leaking now. Hard to tell where it is coming from but it doesn't appear to be the slider, although I supposed it could be. When I tried to get in the back seat to investigate, my rear doors were frozen shut so I can't even get back there to take a closer look. Anyone here had experience in this department?

 

Water and ice don't play nice. You may have had a sliver of ice behind a gasket or seal that let the high pressure water get in there. Let it warm up and try again, maybe with someone inside watching, but for me, I quit using high pressure water around anything i care about.

 

I think what happened was I hit the seal around the slider at an angle and it blew some water past the seal. Probably not a huge deal, but I'll be more careful next time. Much better than if it were leaking around the actual window or the third brake light.