I have 1999 f-150 lightning with 80000 miles
when i'm driving i had the whole truck go dead for about 2 sec. then it comes right back. but every thing just goes dead engine and gages. Its happend 3 times in about 2 weeks. Update Now this is an every day occurrence. I pin pointed it down to when accelerating hard or going over a hard bump. The weird thing is that I can get the radio to glitch on demand by accelerating but nothing else. Still no codes and the battery seems to be fine but haven’t been able to test it under load other then its reading 13.4 v. I think dyotech is right it's a loose wire but where all the bulkhead wire harnesses are tight. Please Help!!!!!

 

Almost has to be a loose wire/ground or connection. Do you have any aftermarket components added? Remote starter etc. If so check the connections. Also check the HDR connection and wire at the front cover just below the A/C compressor. If its loose it will shut you off and back on at random. No codes yet? I have seen some engines with excessive end play have your symptoms when the crank can actually move far enough back that the HDR sensor loses a signal with the HDR crank wheel. Its not real common but happens sometimes.

 

Mine was doing that for awhile and it ended up being the battery connection. I had to retighten the cables on the battery terminals.

 

most likely what j-hoss said.

check the battery connection for tightness and corrosion. if you you see corrosion, peel the insulation back until the wire is clean, cut it there and put on a new terminal.