Electrical Gurus - 87' no keyed power

[wahl4m]

i while back my granddaughters pontiac shoebox -kept dying once in awhile -like yours -her stepdad -kept insisting it was a computer problem!-she even stashed a laptop in her car -to ck -it when it went down! i got the car from her & took it to get a new computer or get it reflashed ?? & a great tech at my son in laws chevy dealer ship found it was a battery BAD -not a very old battery ! put a new "delco in it & have not had any trouble in 6 months !!!!!when the car died -it would still crank & seem ok !