EX-T

OK, I'm thinking my harness is jacked up and I'm gonna try to pin the primary o2 directly to the ECU. I've found the pinouts but need some advice as to how to go about repinning it....

1) Can I ground the 2 black wires at the same place?
2) Exactly what do I do with the signal wire and the shielding around it? I know the shielding goes to the Tstat housing but I'm not sure how to do it?
3) Can I just us splice connectors and just splice into the existing wire the comes from the harness to the ECU on the inside of the car?

TIA! If anyone has already done this and would like to give me some pointers I would greatly appreciate it! Even better, take some pix of how your wiring looks....

EX-T

C'mon...someone has done this!

ImportCracker88

Yo wat up guy......DO NOT CUT THE SIGNAL WIRE, if u do, u might be replacing ur O2..... some cars use the insulation of the wire to get oxygen to the sensor for it to work, so dont mess with it, u might get away with a crimp(with the wax to weatherproof it) but not sure.Yes you can ground wire at the same place, but make sure they are good connections, with alot of contact.What do u mean the signal wire goes to the t-stat housing, if thats true mabye thats ur problem.Sure its not a ground?As long as the wire is coming from the same spot and going to the same spot as it did, u will be alright, just be cautios. hope this helps you, feel free to ask more....later.

EX-T

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ImportCracker88 &raquo;</TD></TR><TR><TD CLASS="quote">Yo wat up guy......DO NOT CUT THE SIGNAL WIRE, if u do, u might be replacing ur O2..... some cars use the insulation of the wire to get oxygen to the sensor for it to work, so dont mess with it, u might get away with a crimp(with the wax to weatherproof it) but not sure.Yes you can ground wire at the same place, but make sure they are good connections, with alot of contact.What do u mean the signal wire goes to the t-stat housing, if thats true mabye thats ur problem.Sure its not a ground?As long as the wire is coming from the same spot and going to the same spot as it did, u will be alright, just be cautios. hope this helps you, feel free to ask more....later.</TD></TR></TABLE>

The signal wire has the shielding and from what I've been told, the shielding goes to the t-stat housing and the wire wire goes to the ecu. That's what I'm confused about.

The shielding protects the signal wire for electrical noise i.e. alternator whine, etc., but the shielding has to be grounded to do so....

EX-T

anyone else?

EX-T

c'mon, somebody!?

likwidchz

I feel your pain.

the sheild wire generally will go to something like ground to the ecu or Signal Ground on obd2 cars

The white signal wire will go to the ecu to the 02 sensor signal in

DO NOT ground both of the black wires

the black wires arnt ground they are 02 sensor heater signal they dont have any specific order they simply need to be connected to a new 02 sensor


one black wire will go to the ecu, the other black wire is actually +12v with the key in position 2 "aka the dash lights light up, battery light exct"


does this answer your question?

EX-T

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by likwidchz &raquo;</TD></TR><TR><TD CLASS="quote">I feel your pain.

the sheild wire generally will go to something like ground to the ecu or Signal Ground on obd2 cars

The white signal wire will go to the ecu to the 02 sensor signal in

DO NOT ground both of the black wires

the black wires arnt ground they are 02 sensor heater signal they dont have any specific order they simply need to be connected to a new 02 sensor


one black wire will go to the ecu, the other black wire is actually +12v with the key in position 2 "aka the dash lights light up, battery light exct"


does this answer your question?</TD></TR></TABLE>

So there's a pin on the ecu called "Signal Ground which is where I ground the sheilding? How would I go about doing this? Strip back enough of the insulation to twist the shielding together and ground it to that pin on the ecu?

likwidchz

QUOTE "So there's a pin on the ecu called "Signal Ground which is where I ground the shielding? How would I go about doing this? Strip back enough of the insulation to twist the shielding together and ground it to that pin on the ecu? "

to answer your question--- No don't do that -- run it to the body ground or right to the neg terminal of the battery.


signal ground is most likely a separated logic style ground off the ecu un related to engine ground.

You could most likely get away with not putting any shielding back however, id simply run that shield to body ground.


sensor ground is used for a couple sensors:
Map
TPS
EGR
IAT

probably a couple others im not listing.

Just take the shield of the wiring and strip it back and run to the body ground "some screw on your car that is bare metal"

The only reason FYI that there are shields on things like the distributor along with the 02 sensor is due to the fact that there shouldn't be un neccessary noise introduced into the lines which would cause the car to run improperly. its the same reason cable tv coax "rg-6" has shielding around it.

FYI if you don't have a shield around your 02 sensor you most likely wont notice a thing although it takes a couple minutes to wire it up and its just something you should do.

Relic1

the ground for the O2 shield runs to the thermostat ground.
the distributor shields are connected to the thermostat ground as well. It's even the same wire. (A25 on OBD1 cars)

likwidchz

It is not A25 as A25 is +12 from main relay if you wired that up you would blow a fuse. You would be better off running it to A23/A24 as its ground from the main relay which also ties into the larger diameter wire from the thermostat.

However you can run ground to literally where ever you want on the engine somewhere onto the battery, however you might as well run it where it was originally as it worked.

ImportCracker88

do u have a 3-wire 02? if so, and the wire colors r wht,blk,blk..... one black is power one is ground, yes the shield of the signal wire needs to be grounded there on the housing(or a good ground) but not the signal wire itself...it should go to the ecm, and both of the heater wires should go to the ecm, or at least the ground, get a diagram and put all the wire from which they came, can it get any easier.

Relic1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by likwidchz &raquo;</TD></TR><TR><TD CLASS="quote">It is not A25 as A25 is +12 from main relay if you wired that up you would blow a fuse. You would be better off running it to A23/A24 as its ground from the main relay which also ties into the larger diameter wire from the thermostat.</TD></TR></TABLE>
my bad, A26. The 5 and 6 look the same (at a glance) in the Helm some times.

Connecting to A25 wouldn't blow a fuse, it would simply raise the shield to 12V. there should be no other connection to it or it could be a power conduit for starter, alternator or some other kind of power. Which would induce noise.