car won't start

Dear All,

I have this grand cherokee 1996 5.2 limited and having great troubles with it
lately. A week ago it started to give the check engine warning which is followed
by the check gauges light. Shortly after the engine stopped while driving,
which was dangerous coz I was on the highway!!, anyways I restarted it and
drove. It happened 4 times after the first time and I took it to a garage. They
changed the battery there along with the mop sensor and the regulator
stabiliser. 24 hours after the new changes made, it stopped again!! right now it
does not start at all, the garage people could not figure it out and called an
electronics specialist. I am open for any suggestions, thanks in advance!!