Wrench symbol, now no start!

[06F-250]

First tow since new head studs,egr delete,& oil cooler were installed a month ago. 200 miles into the trip the wrench symbol lights up. EWT =210,EOT=200 approx. engine power is cut noticeably. Got to destination and parked the truck. A few hours later I was working on a trailer light issue. I turned the key on and off a few times never starting the truck. The next thing I know my message center symbols are flickering and the truck won't even attempt to turn over. Any help is appreciated. Sorry so windy.