Sounds like something worked loose on the power connections? If you are using any kind of spring tensions power connectors like round barrel plugs, that might be something to verify. Also, if you have a common ground wire to the chassis, that might need to be re-scraped to metal and tightened.
I just went through a similar issue (rebooting) on my Camaro's carputer, because my car is so bouncy everything works loose easy. For me it was a crimped on spade lug connection to ground that worked slightly loose, but I found it Sunday after a few hours of sweating it.