Fox Mustangs have a hole/grommet for the wiring on the LH side of the tunnel close to where the bellhousing and trans bolt together.  This is for the backup lights, neutral switch, and speed sensor.  There's no reason not to run the O2 wring that way as well, just make sure it can't lay on the exhaust anywhere.

after a bit of research the Tremec Tko neutral switch apparently requires a relay.  The switch can't handle a full 12v long term so you have to install a relay.  I may or may not install a relay and neutral switch.  

if i decide not to install the neutral switch i'll still run it near the access hole the heat shrink the end of it so if i decide later on i can just pull the wire.  either way i plan to wire up the back up lights.

below is a link i found.  i would have thought that would have been spelled out in the wiring instructions but i guess the neutral switch for an automatic is different than what a tko uses.  I'm running quick fuel carb for now.

Tremec TKO Neutral Safety Switch Wiring - Bing video

6sally6 wrote:

Like BobE sez.........I ran my war thru the.........'shifter-hole'(that coulda been ugly! !!
I mean.....it's there already and its doubtful any vibration would scrub it into in our-life-time!
I vote for the-shifter-hole!!!
6sally6

I slit some small diameter hose and placed on the edge of the floor sheetmetal to preclude chaffing the wires ... its worked so far!

BobE wrote:

TKOPerformance wrote:

 I'm confused about the 12V thought, the switch grounds when the trans is in neutral.  There should never be power connected to it. 

TKO - the neutral switch is in series with the starter solenoid, the switch contacts will see the full current and voltage of the starter solenoid.  This is the way it was set up in our vintage cars.  With the advent of computer control in modern cars, I'm guessing the neutral switch is an input to the computer and would carry significantly less current and therefore the neutral switch is not made as "robust" as in the past.  This would be why the suggestion to use a relay.

Let me back up, my assumption was that he was using a T5 in a vintage Mustang since he referenced O2 sensors and then mentioned the neutral switch.  I see its a TKO, but the T5 and TKO use the same neutral switch since the TKO was designed to replace the T5.  This is where he's having an issue: the switch isn't designed to have power run through it, which is why it can't tolerate 12V for a prolonged period of time.  Its meant to breaker ground.  These instructions are using it as a neutral safety switch like in an automatic.  Personally, I would not wire it like that.  I would forgo a neutral safety switch in a manual trans application and use a clutch pedal switch instead that works the way you are describing (clutch must be in, switch depressed to allow cranking, and the switch is in series with the solenoid). 

6sally6 wrote:

TKOPerformance wrote:

BobE wrote:

use a clutch pedal switch instead that works the way you are describing (clutch must be in, switch depressed to allow cranking, and the switch is in series with the solenoid). 

Just more stuff to go worng.........IMHO!
6s6
 

6s6 - I agree, and did not wire in the neutral switch on my T-5.  However, I know of a few instances where someone reached in to start the car and didn't realize that they left in gear.  Lead to either the car nose diving into the garage door or the garage rear wall, or the guy chasing the car ... this happened one time at a car show, the results were not pretty.
 

Switch on side of transmission is backup lights.
Switch on top of transmission is for EEC-IV Neutral sensing switch...required to pull codes.

If using top switch as a neutral safety ( wasn’t designed for high current), use a relay.