I have this strange problem witha 2017 Power. Mostly when the road is slushy or has been snowing, sometimes when it rains... sometimes when it gets washed.... put the key in and the gauges are dead, just a slight flicker from the needles. No start, things dry out and usually fixes the issue. Sometimes CEL on sometimes not. The first time it happened I shut the truck off and when I went to start it again....NO start... we opened the hood disconnected battery...no luck... called tow truck... as he was pulling in the parking lot we slammed the hood shut... everything worked normally, truck started off we went.. The problem only happens when it has snowed, sometimes when it rains and sometimes when you wash it. Dash goes nuts, gauges dead, all lights that can be on are on, wipers go and go and go service electronic brake message, service trailer brake message, NO BUS in mileage display, today was new no speedo reading...Took it to dealer last winter when it happened... had 90 stored codes, couldn't duplicate problem.... of course.... therefore no fix....

fast forward about a year later, the problem has gotten worse. Every time it snows symptoms arise. Slamming hood was suspicious, we started checking what could the hood have to do with it. so when the problem occurred again we started messing with stuff in the engine compartment. start bangin on electrical systems.... as a joke i smacked the cap of the brake reservoir... TADA! So now every time it acts us i pop the hood, smack the cap.. sometimes have to jiggle the whole master cylinder and I can get the truck to start usually..... Its got an appointment next week at ram dealer, but like usual, the problem wont occur for them and there will be no fix......

moral of the story just smack or move around your break fluid reservoir... Isn't that the strangest damn thing????

I need some help.... We have checked for water coming down firewall inside and out... nothing... checked for water in the engine bay... nothing. Why in the world would it have anything to do with break reservoir and master cylinder?????

 

UPDATE: if you just apply pressure straight downward on the cap of the brake reservoir, you can get the truck started... Gauges are still wack on the dash but at least its running....

 

I was going to suggest taking a look at the TIPM for water / moisture instrusion, but your finding related to applying pressure to the brake reservoir really throws me off. How strange!

-Rod