eec power ground problem need a wiring genius

[1stanger1]

heres the deal i just shoved this 302 into my 99 mustang its fuel injected btw...

eec is an A9L and as far as i can tell i have a 91-93 eec harness

now being that this stuff is older i have to hard wire it into the car....i have evrything else figured out and already had a running crappy fuel injected 302 in it....however somehting with this wiring isnt right

pin 37 57 are for vehicle power wich are hot when switched on..
pin 1 is constant 12v
if pin 40 and 60 are power grounds then why the hell do they start melting while connecting them to ground...every diagram i have seen so far is showing 40 and 60 as a power ground doesnt matter what color the wires are they all show it going straight to the battery...when i do this they get hot...and arc and with these wires not hooked up my eec relay isnt going to function and i'm not getting my signal from pin 19 to the fuel pump relay i do have power from pin 22 to the pump relay but not 19 which is a ground signal

if you need to know what i have hooked up so far let me know i'll post it

 

[1stanger1]

never mind i got it....seemed there was a broken wire that i missed and was grounding to a painted surface cause a low voltage reading at my grounds.. therofore causing it to spark when i hooked it up....

 

[jrichker]

What connects where in the ground wiring:
The picture shows the common ground point for the battery , computer, & extra 3G alternator ground wire as described above in paragraph 2. A screwdriver points to the bolt that is the common ground point.

The battery common ground is a 10 gauge pigtail with the computer ground attached to it.
Picture courtesy timewarped1972

Correct negative battery ground cable.

The computer has its own dedicated power ground that comes off the ground pigtail on the battery ground wire. Due to its proximity to the battery, it may become corroded by acid fumes from the battery.
In 86-90 model cars, it is a black cylinder about 2 1/2" long by 1" diameter with a black/lt green wire.
In 91-95 model cars it is a black cylinder about 2 1/2" long by 1" diameter with a black/white wire.
You'll find it up next to the starter solenoid where the wire goes into the wiring harness.