Sounds like you've been over it all and what I'm about to say likely doesn't
apply, but I'll say it just in case.  The alternator (voltage regulator in
it?) went bad in our 94 Trooper...voltage would spike, headlights got bright
(if it was after dark), and the vehicle would buck and cause the "check
transmission" like to trip on (presumably when the computer cut out due to
high voltage).  Of course if you happened to be looking when it did it, you
could see the voltage meter jump up...

Afraid I'm no help on locating that specific wire...

Good luck!

Wesley

am driving a trooper 92, automatic dohc 3.2
could someone tell me where to look for the ground wire(s) or connection as described
in this article?

http://www.misterfixit.com/izuzzu.htm

some months ago, I recall reading here or isuzu forum a recommendation to install an
additional ground wire between transmission and engine or transmission and shiny part
of car body.

the reason I am asking is unexplained loss of power (total blackout, no computer
codes), which happens randomly and I suspect the problem is similar for what is
described in the article above. I do not have the bucking problem and trooper has all
new sensors, O2, IAC, TPS, MAF and coils, harness and plugs. alternator and starter
have been totally serviced and overhauled and are in perfect condition, new battery
too

is the ground wire install as simple as just getting any flat copper wire, short piece
and screwing it to any part of the transmission and body of car? or does it make a
difference as to gauge or type of ground wire used or location to engine rather than
body of car?