breakout box, grounds 40 & 60, ohms reading koeo, koer ... help!!!

Note that all resistance tests must be done with power off. Measuring resistance
with a circuit powered on will give false readings and possibly damage the meter.

The computer has its own dedicated power ground that
comes off the ground pigtail on the battery ground wire. Due to
it's proximity to the battery, it may become corroded by acid
fumes from the battery. It is a black cylinder about 2 1/2" long
by 1" diameter with a black/lt green wire. It looks kind of like
an inline fuse holder You'll find it up next to the starter solenoid
where the wire goes into the wiring harness. The computer's main
power ground (the one that comes from the battery ground wire)
uses pins 40 & 60 for all the things it controls internally.

Picture courtesy timewarped1972


Diagram courtesy of Tmoss & Stang&2birds


See the following website for some help from Tmoss (diagram designer)
& Stang&2Birds (website host) for help on 88-95 wiring
http://www.veryuseful.com/mustang/tech/engine/

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif