Anyone using a lincoln injector harness come inside

I think the HEGO ground on the A9L puter runs to the firewall, not the block.

83Mustang427TT said:

TTT does it run to the block or the firewall?

Click to expand...

Either one will do as long asyour block to body ground is good.

1.) The main power ground is from engine block to battery: it is
the power ground for the starter & alternator.

2.) The secondary power ground is between the back of the
intake manifold and the driver's side firewall. It is often missing or
loose. It supplies ground for the alternator, A/C compressor
clutch and other electrical accessories such as the gauges.
Any car that has a 3G or high output current alternator needs
a 4 gauge ground wire running from the block to the chassis
ground where the battery pigtail ground connects.
The 3G has a 130 amp capacity, so you wire the power side
with 4 gauge wire. It stands to reason that the ground side
handles just a much current, so it needs to be 4 gauge too.

Picture courtesy timewarped1972

3.) 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.You'll find it up next to
the starter solenoid where the wire goes into the wiring harness